Sigmoidoscopy

Definition
Purpose
Demographics
Description
Diagnosis/Preparation
Aftercare
Risks
Normal results
Morbidity and mortality rates
Alternatives

Definition

Sigmoidoscopy is a diagnostic and screening procedure in which a rigid or flexible tube with a camera on the end (a sigmoidoscope) is inserted into the anus to examine the rectum and lower colon (bowel) for bowel disease, cancer, precancerous conditions, or causes of bleeding or pain.

Purpose

Sigmoidoscopy is used most often in screening for colorectal cancer or to determine the cause of rectal bleeding. It is also used in diagnosis of inflammatory bowel disease, microscopic and ulcerative colitis, and Crohn’s disease.

Cancer of the rectum and colon is the second most common cancer in the United States. About 148,300 new cases are diagnosed annually. Between 55,000 and 60,000 Americans die each year of cancer in the colon or rectum.

After reviewing a number of studies, experts recommend that people over 50 be screened for colorectal cancer using sigmoidoscopy every three to five years. Individuals with inflammatory bowel conditions such as Crohn’s disease or ulcerative colitis, and thus at increased risk for colorectal cancer, may begin their screenings at a younger age, depending on when their disease was diagnosed. Many physicians screen such persons more often than every three to five years. Screening should also be performed in people who have a family history of colon or rectal cancer, or small growths in the colon (polyps).

Some physicians do this screening with a colonoscope, which allows them to see the entire colon. Most physicians prefer sigmoidoscopy, which is less time-consuming, less uncomfortable, and less costly.

Studies have shown that one-quarter to one-third of all precancerous or small cancerous growths can be seen with a sigmoidoscope. About one-half are found with a 1 ft (30 cm) scope, and two-thirds to three-quarters can be seen using a 2 ft (60 cm) scope.

In some cases, the sigmoidoscope can be used therapeutically in conjunction with other equipment such as electrosurgical devices to remove polyps and other lesions found during the sigmoidoscopy.

Demographics

Experts estimate that in excess of 525,000 sigmoidoscopy procedures are performed each year. This number includes most of the persons who are diagnosed with colon cancer each year, a greater number who are screened and receive negative results, persons who have been treated for colon conditions and receive a sigmoidoscopy as a follow-up procedure, and individuals who are diagnosed with other diseases of the large colon.

Description

Sigmoidoscopy may be performed using either a rigid or flexible sigmoidoscope. A sigmoidoscope is a thin tube with fiberoptics, electronics, a light source, and camera. A physician inserts the sigmoidoscope into the anus to examine the rectum (the first 1 ft [30cm] of the colon) and its interior walls. If a 2 ft (60 cm) scope is used, the next portion of the colon can also be examined for any irregularities. The camera of the sigmoidoscope is connected to a viewing monitor, allowing the interior of the rectum and colon to be enlarged and viewed on the monitor. Images can then be recorded as still pictures or the entire procedure can be videotaped. The still pictures are useful for comparison purposes with the results of future sigmoidoscopic examinations.

If polyps, lesions, or other suspicious areas are found, the physician biopsies them for analysis. During the sigmoidoscopy, the physician may also use forceps, graspers, snares, or electrosurgical devices to remove polyps, lesions, or tumors.

A typical sigmoidoscopy procedure requires 15 to 20 minutes to perform. Preparation begins one day before the procedure. There is some discomfort when the scope is inserted and throughout the procedure, similar to that experienced when a physician performs a rectal exam using a finger to test for occult blood in the stool (another important screening test for colorectal cancer). Individuals may also feel some minor cramping pain. There is rarely severe pain, except for persons with active inflammatory bowel disease.

Private insurance plans almost always cover the cost of sigmoidoscopy examinations for screening in healthy individuals over 50, or for diagnostic purposes. Medicare covers the cost for diagnostic exams, and may cover the costs for screening exams. Medicaid benefits vary by state, but sigmoidoscopy is not a covered procedure in many states. Some community health clinics offer the

KEY TERMS

Biopsy— The removal of a small portion of tissue during sigmoidoscopy to perform laboratory tests to determine if the tissue is cancerous.

Colonoscopy— A diagnostic endoscopic procedure that uses a long flexible tube called a colonoscope to examine the inner lining of the entire colon; may be used for colorectal cancer screening or for a more thorough examination of the colon.

Colorectal cancer— Cancer of the large intestine, or colon, including the rectum.

Electrosurgical device— A medical device that uses electrical current to cauterize or coagulate tissue during surgical procedures, often used in conjunction with laparoscopy, colonoscopy, or sigmoidoscopy.

Inflammatory bowel diseases— Ulcerative colitis or Crohn’s disease: chronic conditions characterized by periods of diarrhea, bloating, abdominal cramps, and pain, sometimes accompanied by weight loss and malnutrition because of the inability to absorb nutrients.

Pathologist— A doctor who specializes in the diagnosis of disease by studying cells and tissues under a microscope.

Polyp— A small growth, usually not cancerous, but often precancerous when it appears in the colon.

procedure at reduced cost, but this can only be done if a local gastroenterologist (a physician who specializes in treating stomach and intestinal disorders) is willing to donate personal time to perform the procedure.

Diagnosis/Preparation

The purpose of preparation for sigmoidoscopy is to cleanse the lower bowel of fecal material or stool so the physician can see the lining. Preparation begins 24 hours before the procedure, when an individual must begin a clear liquid diet. Preparation kits are available in drug stores. In normal preparation, about 20 hours before the exam, a person begins taking a series of laxatives, which may be oral tablets or liquid. The individual must stop drinking any liquid four hours before the exam. An hour or two prior to the examination, the person uses an enema or laxative suppository to finish cleansing the lower bowel.

Individuals need to be careful about medications before having sigmoidoscopy. They should not take aspirin, products containing aspirin, or products containing ibuprofen for one week prior to the exam, because these medications can exacerbate bleeding during the procedure. They should not take any iron or vitamins with iron for one week prior to the exam, since iron can cause color changes in the bowel lining that interfere with the examination. They should take any routine prescription medications, but may need to stop certain medications. Prescribing physicians should be consulted regarding routine prescriptions and their possible effect(s) on sigmoidoscopy.

Individuals with renal insufficiency or congestive heart failure need to be prepared in an alternative way, and must be carefully monitored during the procedure.

Aftercare

There is no specific aftercare necessary following sigmoidoscopy. If a biopsy was taken, a small amount of blood may appear in the next stool. Persons should be encouraged to pass gas following the procedure to relieve any bloating or cramping that may occur after the procedure. In addition, an infection may develop following sigmoidoscopy. Persons should be instructed to call their physician if a fever or pain in the abdomen develops over the few days after the procedure.

Risks

There is a slight risk of bleeding from the procedure. This risk is heightened in individuals whose blood does not clot well, either due to disease or medication, and in those with active inflammatory bowel disease. Rarely, trauma to the bowel or other organs can occur, resulting in an injury (perforation) that must be repaired, or peritonitis, which must be treated with medication.

Sigmoidoscopy may be contraindicated in persons with severe active colitis or toxic megacolon (an extremely dilated colon). In general, people experiencing continuous ambulatory peritoneal dialysis are not candidates due to a high risk of developing intraperitoneal bleeding.

Normal results

The results of a normal examination reveal a smooth colon wall, with sufficient blood vessels for good blood flow.

Morbidity and mortality rates

For a cancer screening sigmoidoscopy, an abnormal result is one or more noncancerous or precancerous polyps, or clearly cancerous polyps. People with polyps have an increased risk of developing colorectal cancer in the future and may be required to undergo

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?

A colonoscopy procedure is usually performed by a gastroenterologist, a physician with specialized training in diseases of the colon. Alternatively, general surgeons or experienced family physicians perform sigmoidoscopic examinations. In the United States, the procedure is usually performed in an outpatient facility of a hospital or in a physician’s professional office.

Persons with rectal bleeding may need full colonoscopy in a hospital setting. Individuals whose blood does not clot well (possibly as a result of blood-thinning medications) may require the procedure to be performed in a hospital setting.

additional procedures such as colonoscopy or more frequent sigmoidoscopic examinations.

Small polyps can be completely removed. Larger polyps may require the physician to remove a portion of the growth for laboratory biopsy. Depending on the laboratory results, a person is then scheduled to have the polyp removed surgically, either as an urgent matter if it is cancerous, or as an elective procedure within a few months if it is noncancerous.

In a diagnostic sigmoidoscopy, an abnormal result shows signs of active inflammatory bowel disease, either a thickening of the intestinal lining consistent with ulcerative colitis, or ulcerations or fissures consistent with Crohn’s disease.

Mortality from a sigmoidoscopy examination is rare and is usually due to uncontrolled bleeding or perforation of the colon.

Alternatives

A screening examination for colorectal cancer is a test for fecal occult blood. A dab of fecal material from toilet tissue is smeared onto a card. The card is treated in a laboratory to reveal the presence of bleeding. This test is normally performed prior to a sigmoidoscopic examination.

A less invasive alternative to a sigmoidoscopic examination is an X-ray of the colon and rectum. Barium is used to coat the inner walls of the colon. This lower GI (gastrointestinal) X-ray may reveal the outlines of suspicious or abnormal structures. It has the disadvantage of not allowing direct visualization

QUESTIONS TO ASK THE DOCTOR

• Is the supervising physician appropriately certified to conduct a sigmoidoscopy?
• How many sigmoidoscopy procedures has the doctor performed?
• What other steps will be taken as a result of my test findings?

of the colon. It is less costly than a sigmoidoscopic examination.

A more invasive procedure is direct visualization of the colon during surgery. This procedure is rarely performed in the United States.

Resources

BOOKS

Balakrishnan, V., ed. Practical Gastroenterology, 3rd ed. Tunbridge Wells, Kent, UK: Anshan Ltd., 2007.

Gershman, G., and M. Ament. Practical Pediatric Gastrointestinal Endoscopy. New York: Wiley, 2007.

Gillison, W., and H. Buchwald. Pioneers in Surgical Gastroenterology. Shrewsbury, Shropshire, UK: TFM Publishing, 2006.

Johns Hopkins Medical Guide to Health After 50. New York: Black Dog and Leventhal Publishers, 2006.

PERIODICALS

Kronborg, O., and J. Regula. “Population screening for colorectal cancer: advantages and drawbacks.” Digestive Diseases 25, no. 3 (2007): 270–273.

Levy, B. T., T. Nordin, S. Sinift, M. Rosenbaum, and P. A. James. “Why hasn’t this patient been screened for colon cancer? An Iowa Research Network study.” Journal of the American Board of Family Medicine 20, no. 5 (September-October 2007): 458–468.

Mandel, J. S. “Which colorectal cancer screening test is best?” Journal of the National Cancer Institute 99, no. 19 (October 2007): 1424–1425.

O’Mahony, S. “Endoscopy in pregnancy.” Best Practice an Research in Clinical Gastroenterology 21, no. 5 (2007)893–899.

Winawer, S. J. “The multidisciplinary management of gastrointestinal cancer; colorectal cancer screening.” Best Practice and Research in Clinical Gastroenterology 21, no. 6 (2007): 1031–1048.

OTHER

“Flexible Sigmoidoscopy.” National Digestive Diseases Information Clearinghouse. November 2004. http://www.niddk.nih.gov/health/digest/pubs/diagtest/sigmo.htm (December 31, 2007).

“Frequently Asked Questions about Colonscopy and Sigmoidoscopy,” American Cancer Society. February 7, 2008. http://search.cancer.org/search?client=amcancer&site=amcancer&output=xml_no_dtd&proxystylesheet=amcancer&restrict=cancer&q=sigmoidoscopy (April 6, 2008).

Information about Sigmoidoscopy. Center of Excellence for Medical Multimedia. Video. http://www.colonscope.org/ (December 31, 2007).

Johnson, B. A. “Flexible Sigmoidoscopy: Screening for Colorectal Cancer.” American Family Physician. January 15, 1999. http://www.aafp.org/afp/990115ap/313.html (December 31, 2007).

“Sigmoidoscopy.” Medical Encyclopedia. Medline Plus. May 8, 2006. http://www.nlm.nih.gov/medlineplus/ency/article/003885.htm (December 31, 2007).

“Six Questions that Could Save Your Life (Or the Life of Someone You Love): What Women Need to Know about Colon Cancer Screening.” American Society for Gastrointestinal Endoscopy. 2007. http://www.asge.org/PatientInfoIndex.aspx?id=374 (April 6, 2008).

ORGANIZATIONS

American Academy of Family Physicians, 11400 Tomahawk Creek Parkway, Leawood, KS, 66211-2672, (913) 906-6000, (800) 274-2237, http://www.aafp.org.

American College of Surgeons, 633 North Saint Claire Street, Chicago, IL, 60611, (312) 202-5000, http://www.facs.org/.

American Society for Gastrointestinal Endoscopy, 1520 Kensington Road, Suite 202, Oak Brook, IL, 60523, (630) 573-0600, http://www.asge.org.

Society of American Gastrointestinal Endoscopic Surgeons, 11300 West Olympic Boulevard, Suite 600, Los Angeles, CA, 90064, (310) 437-0544, (310) 437-0585, http://www.sages.org.

L. Fleming Fallon, Jr., M.D., Dr.P.H

Sigmoidoscopy

Definition

Sigmoidoscopy is a diagnostic and screening procedure in which a rigid or flexible tube with a camera on the end (a sigmoidoscope) is inserted into the anus to examine the rectum and lower colon (bowel) for bowel disease, cancer, precancerous conditions, or causes of bleeding or pain.

Purpose

Sigmoidoscopy is used most often in screening for colorectal cancer or to determine the cause of rectal bleeding. It is also used in diagnosis of inflammatory bowel disease, microscopic and ulcerative colitis, and Crohn's disease.

Cancer of the rectum and colon is the second most common cancer in the United States. About 155,000 cases are diagnosed annually. Between 55,000 and 60,000 Americans die each year of cancer in the colon or rectum.

After reviewing a number of studies, experts recommend that people over 50 be screened for colorectal cancer using sigmoidoscopy every three to five years. Individuals with such inflammatory bowel conditions as Crohn's disease or ulcerative colitis, and thus are at increased risk for colorectal cancer, may begin their screenings at a younger age, depending on when their disease was diagnosed. Many physicians screen such persons more often than every three to five years. Screening should also be performed in people who have a family history of colon or rectal cancer, or small growths in the colon (polyps).

Some physicians do this screening with a colonoscope, which allows them to see the entire colon. However, most physicians prefer sigmoidoscopy, which is less time-consuming, less uncomfortable, and less costly.

Studies have shown that one-quarter to one-third of all precancerous or small cancerous growths can be seen with a sigmoidoscope. About one-half are found with a 1 ft (30 cm) scope, and two-thirds to three-quarters can be seen using a 2 ft (60 cm) scope.

In some cases, the sigmoidoscope can be used therapeutically in conjunction with such other equipment as electrosurgical devices to remove polyps and other lesions found during the sigmoidoscopy.

Demographics

Experts estimate that in excess of 500,000 sigmoidoscopy procedures are performed each year. This number includes most of the persons who are diagnosed with colon cancer each year, a greater number who are screened and receive negative results, persons who have been treated for colon conditions and receive a sigmoidoscopy as a follow-up procedure, and individuals who are diagnosed with other diseases of the large colon.

Description

Sigmoidoscopy may be performed using either a rigid or flexible sigmoidoscope. A sigmoidoscope is a thin tube with fiberoptics, electronics, a light source, and camera. A physician inserts the sigmoidoscope into the anus to examine the rectum (the first 1 ft [30 cm] of the colon) and its interior walls. If a 2 ft (60 cm) scope is used, the next portion of the colon can also be examined for any irregularities. The camera of the sigmoidoscope is connected to a viewing monitor, allowing the interior of the rectum and colon to be enlarged and viewed on the monitor. Images can then be recorded as still pictures or the entire procedure can be videotaped. The still pictures are useful for comparison purposes with the results of future sigmoidoscopic examinations.

If polyps, lesions, or other suspicious areas are found, the physician biopsies them for analysis. During the sigmoidoscopy, the physician may also use forceps, graspers, snares, or electrosurgical devices to remove polyps, lesions, or tumors.

The sigmoidoscopy procedure requires five to 20 minutes to perform. Preparation begins one day before the procedure. There is some discomfort when the scope is inserted and throughout the procedure, similar to that experienced when a physician performs a rectal exam using a finger to test for occult blood in the stool (another important screening test for colorectal cancer). Individuals may also feel some minor cramping pain. There is rarely severe pain, except for persons with active inflammatory bowel disease.

Private insurance plans almost always cover the cost of sigmoidoscopy examinations for screening in healthy individuals over 50, or for diagnostic purposes. Medicare covers the cost for diagnostic exams, and may cover the costs for screening exams. Medicaid benefits vary by state, but sigmoidoscopy is not a covered procedure in many states. Some community health clinics offer the procedure at reduced cost, but this can only be done if a local gastroenterologist (a physician who specializes in treating stomach and intestinal disorders) is willing to donate personal time to perform the procedure.

Diagnosis/Preparation

The purpose of preparation for sigmoidoscopy is to cleanse the lower bowel of fecal material or stool so the physician can see the lining. Preparation begins 24 hours before the procedure, when an individual must begin a clear liquid diet. Preparation kits are available in drug stores. In normal preparation, about 20 hours before the exam, a person begins taking a series of laxatives , which may be oral tablets or liquid. The individual must stop drinking any liquid four hours before the exam. An hour or two prior to the examination, the person uses an enema or laxative suppository to finish cleansing the lower bowel.

Individuals need to be careful about medications before having sigmoidoscopy. They should not take aspirin , products containing aspirin, or products containing ibuprofen for one week prior to the exam, because these medications can exacerbate bleeding during the procedure. They should not take any iron or vitamins with iron for one week prior to the exam, since iron can cause color changes in the bowel lining that interfere with the examination. They should take any routine prescription medications, but may need to stop certain medications. Prescribing physicians should be consulted regarding routine prescriptions and their possible effect(s) on sigmoidoscopy.

Individuals with renal insufficiency or congestive heart failure need to be prepared in an alternative way, and must be carefully monitored during the procedure.

Aftercare

There is no specific aftercare necessary following sigmoidoscopy. If a biopsy was taken, a small amount of blood may appear in the next stool. Persons should be encouraged to pass gas following the procedure to relieve any bloating or cramping that may occur after the procedure. In addition, an infection may develop following sigmoidoscopy. Persons should be instructed to call their physician if a fever or pain in the abdomen develops over the few days after the procedure.

Risks

There is a slight risk of bleeding from the procedure. This risk is heightened in individuals whose blood does not clot well, either due to disease or medication, and in those with active inflammatory bowel disease. Rarely, trauma to the bowel or other organs can occur, resulting in an injury (perforation) that must be repaired, or peritonitis, which must be treated with medication.

Sigmoidoscopy may be contraindicated in persons with severe active colitis or toxic megacolon (an extremely dilated colon). In general, people experiencing continuous ambulatory peritoneal dialysis are not candidates due to a high risk of developing intraperitoneal bleeding.

Normal results

The results of a normal examination reveal a smooth colon wall, with sufficient blood vessels for good blood flow.

Morbidity and mortality rates

For a cancer screening sigmoidoscopy, an abnormal result is one or more noncancerous or precancerous polyps, or clearly cancerous polyps. People with polyps have an increased risk of developing colorectal cancer in the future and may be required to undergo additional procedures such as colonoscopy or more frequent sigmoidoscopic examinations.

Small polyps can be completely removed. Larger polyps may require the physician to remove a portion of the growth for laboratory biopsy. Depending on the laboratory results, a person is then scheduled to have the polyp removed surgically, either as an urgent matter if it is cancerous, or as an elective procedure within a few months if it is non-cancerous.

In a diagnostic sigmoidoscopy, an abnormal result shows signs of active inflammatory bowel disease, either a thickening of the intestinal lining consistent with ulcerative colitis, or ulcerations or fissures consistent with Crohn's disease.

Mortality from a sigmoidoscopy examination is rare and is usually due to uncontrolled bleeding or perforation of the colon.

Alternatives

A screening examination for colorectal cancer is a test for fecal occult blood. A dab of fecal material from toilet tissue is smeared onto a card. The card is treated in a laboratory to reveal the presence of bleeding. This test is normally performed prior to a sigmoidoscopic examination.

A less invasive alternative to a sigmoidoscopic examination is an x ray of the colon and rectum. Barium is used to coat the inner walls of the colon. This lower GI (gastrointestinal) x ray may reveal the outlines of suspicious or abnormal structures. It has the disadvantage of not allowing direct visualization of the colon. It is less costly than a sigmoidoscopic examination.

A more invasive procedure is direct visualization of the colon during surgery. This procesdure is rarely performed in the United States.

See also Colonoscopy; Cystoscopy.

Resources

books

bland, k. i., w. g. cioffi, and m. g. sarr. practice of general surgery. philadelphia: saunders, 2001.

grace, p. a., a. cuschieri, d. rowley, n. borley, and a. darzi. clinical surgery, 2nd edition. london: blackwell publishers, 2003.

miller, b. e. atlas of sigmoidoscopy and cytoscopy. boca raton, fl: crc press, 2001.

schwartz, s. i., j. e. fischer, f. c. spencer, g. t. shires, and j. m. daly. principles of surgery, 7th edition. new york: mcgraw hill, 1998.

townsend, c., k. l. mattox, r. d. beauchamp, b. m. evers, and d. c. sabiston. sabiston's review of surgery, 3rd edition. philadelphia: saunders, 2001.

wigton, r. s. flexible sigmoidoscopy and other gastrointestinal procedures. st. louis: mosby-year book, 2000.

periodicals

mandel, j. s. "sigmoidoscopy screening probably works, but how well is still unknown." journal of the national cancer institute 95, no.8 (2003): 571–573.

nelson, d. e., j. bolen, s. marcus, h. e. wells, and h. meissner. "cancer screening estimates for u.s. metropolitan areas." american journal of preventive medicine 24, no.4 (2003): 301–309.

newcomb, p. a., b. e. storer, l. m. morimoto, a. templeton, and j. d. potter. "long-term efficacy of sigmoidoscopy in the reduction of colorectal cancer incidence." journal of the national cancer institute 95, no.8 (2003): 622–625.

walsh, j. m., and j. p. terdiman. "colorectal cancer screening: clinical applications." journal of the american medical association 289, no.10 (2003): 1297–1302.

walsh, j. m., and j. p. terdiman. "colorectal cancer screening: scientific review." journal of the american medical association 289, no.10 (2003): 1288–1296.

organizations

american academy of family physicians. 11400 tomahawk creek parkway, leawood, ks 66211-2672. (913) 906-6000. e-mail: <[email protected]>. <http://www.aafp.org>.

american college of surgeons. 633 north st. clair street, chicago, il 60611-32311. (312) 202-5000, fax: (312) 202-5001. e-mail: <[email protected]>. <http://www.facs.org>.

american society for gastrointestinal endoscopy. 1520 kensington road, suite 202, oak brook, il 60523. (630) 573-0600, fax: (630) 573-0691. e-mail: <[email protected]>. <http://www.asge.org>.

society of american gastrointestinal endoscopic surgeons. 2716 ocean park blvd., suite 3000, santa monica, ca 90405. (310) 314-2404, fax: (310) 314-2585. e-mail: <[email protected]>. <http://www.sages.org>.

other

american academy of family physicians [cited may 5, 2003] <http://www.aafp.org/afp/990115ap/313.html>.

american cancer society. [cited may 5, 2003] <http://www.cancer.org/docroot/spc/content/spc_1_colonoscopy_and_sigmoidoscopy_faq.asp>.

american society for gastrointestinal endoscopy. [cited may 5, 2003] <http://www.asge.org/gui/patient/flex.asp>.

colonoscope.org . [cited may 5, 2003] <http://www.colonscope.org/hbw/your_colon.asp>.

national institute of diabetes and digestive and kidney diseases. [cited may 5, 2003] <http://www.niddk.nih.gov/health/digest/pubs/diagtest/sigmo.htm>.

national library of medicine. [cited may 5, 2003] <http://www.nlm.nih.gov/medlineplus/ency/article/003885.htm>.

society of american gastrointestinal and endoscopic surgeons. [cited may 5, 2003] <http://www.sages.org/pi_flexible_sigmoidoscopy.html>.

L. Fleming Fallon, Jr, MD, DrPH

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?

A colonoscopy procedure is usually performed by a gastroenterologist, a physician with specialized training in diseases of the colon. Alternatively, general surgeons or experienced family physicians perform sigmoidoscopic examinations. In the United States, the procedure is usually performed in an outpatient facility of a hospital or in a physician's professional office.

Persons with rectal bleeding may need a full colonoscopy in a hospital setting. Individuals whose blood does not clot well (possibly as a result of blood-thinning medications) may require the procedure to be performed in a hospital setting.

QUESTIONS TO ASK THE DOCTOR

• Is the supervising physician appropriately certified to conduct a sigmoidoscopy?
• How many sigmoidoscopy procedures has the doctor performed?
• What other steps will be taken as a result of my test findings?

Sigmoidoscopy

Definition

Sigmoidoscopy is a diagnostic and screening procedure in which a rigid or flexible tube with a camera on the end (a sigmoidoscope) is inserted into the anus to examine the rectum and lower colon (bowel) for bowel disease, cancer , precancerous conditions, or causes of bleeding and pain .

Purpose

Sigmoidoscopy is used most often in screening for colorectal cancer or to determine the cause of rectal bleeding. It is also used in diagnosis of inflammatory bowel disease, microscopic and ulcerative colitis, and Crohn's disease .

Cancer of the rectum and colon is the second most common cancer in the United States. About 155,000 cases are diagnosed annually. About 55,000–60,000 Americans die each year of colorectal cancer.

A number of studies have suggested, and it is now recommended by cancer authorities that people over 50 be screened for colorectal cancer using endoscopy every three to five years. Individuals with inflammatory bowel disease, such as Crohn's disease or ulcerative colitis, who are at increased risk for colorectal cancer, may begin their screenings at a younger age, depending on when their disease was diagnosed. Many physicians screen such patients more often than every three to five years. Screening should also be done in patients who have a family history of colon or rectal cancer or small growths in the colon (polyps).

Some physicians do this screening with a colono-scope, which allows them to see the entire colon. However, most physicians prefer sigmoidoscopy, which is less time consuming, less uncomfortable, and less costly.

Studies have shown that one quarter to one-third of all precancerous or small cancerous growths can be seen with a sigmoidoscope. About one-half are found with a 1 ft (30 cm) scope, and two-thirds to three-quarters can be seen using a 2 ft (60 cm) scope.

In some cases, the sigmoidoscope can be used therapeutically in conjunction with other equipment, such as electrosurgical devices, to remove polyps and other lesions found during the sigmoidoscopy.

Precautions

Sigmoidoscopy can usually be conducted in a physician's office or an outpatient clinic. However, some individuals should have the procedure done in a hospital day-surgery facility. Those with rectal bleeding may need full colonoscopy in a hospital setting. Patients whose blood does not clot well (possibly as a result of blood thinning medications) may need the procedure performed in a hospital setting as well.

Individuals with renal insufficiency or congestive heart failure need to be prepared in an alternative way, and must be carefully monitored during the procedure.

Sigmoidoscopy may be contraindicated in patients with severe active colitis or toxic megacolon (an extremely dilated colon). In general, patients on continuous ambulatory peritoneal dialysis are not candidates due to a high risk of developing intraperitoneal bleeding.

Description

Sigmoidoscopy may be performed using either a rigid or flexible sigmoidoscope, a thin tube with fiberoptics, electronics, a light source, and camera. The physician inserts the sigmoidoscope into the anus to examine the rectum (the first 1 ft/30 cm of the colon) and its interior walls. If a 2 ft/60 cm scope is used, the next portion of the colon can also be examined for any irregularities. The sigmoidoscope's camera is connected to a viewing monitor (television screen), so the rectum and colon are enlarged and viewed on a monitor. Images can then be recorded as still pictures for hard copy or the entire procedure can be videotaped.

If polyps, lesions, or other suspicious areas are found, the physician biopsies them for analysis. During the sigmoidoscopy, the physician may also use forceps,

KEY TERMS

Biopsy —The removal a small portion of tissue during sigmoidoscopy to perform laboratory tests to determine if the tissue is cancerous.

Colonoscopy —A diagnostic endoscopic procedure that uses a long flexible tube called a colonoscope to examine the inner lining of the entire colon; used for colorectal cancer screening and more thorough examination of the colon.

Colorectal cancer —Cancer of the large intestine, or colon, including the rectum (the last 16 in of the large intestine before the anus).

Congestive heart failure —Excess fluid accumulation in the lungs and surrounding tissues due to the weakness of the heart muscle and the inability to pump sufficiently.

Electrosurgical device —A medical device that uses electrical current to cauterize or coagulate tissue during surgical procedures, often used in conjunction with laparoscopy.

Inflammatory bowel disease —Ulcerative colitis or Crohn's disease; chronic conditions characterized by periods of diarrhea, bloating, abdominal cramps, and pain, sometimes accompanied by weight loss and malnutrition because of the inability to absorb nutrients.

Pathologist —A doctor who specializes in the diagnosis of disease by studying cells and tissues under a microscope.

Polyp —A small growth, usually not cancerous, but often precancerous when it appears in the colon.

Renal insufficiency —The inability of the kidneys to process fluid fast enough to flush the body of impurities.

graspers, snares, or electrosurgical devices to remove polyps, lesions, or tumors.

The sigmoidoscopy procedure takes five to 20 min utes. Preparation begins one day before the procedure. There is some discomfort when the scope is inserted and throughout the procedure, similar to that experienced when a physician performs a rectal exam using a finger to test for occult blood in the stool (another major colorectal cancer screening test). The patient may also feel some minor cramping pain. There is rarely severe pain, except for individuals with active inflammatory bowel disease.

Private insurance plans almost always cover the $150 to $200 cost of sigmoidoscopy for screening in healthy individuals over 50, or for diagnostic purposes. Medicare covers the cost for diagnostic exams, and may cover the costs for screening exams. Medicaid varies by state, but does not cover the procedure in most states. Some community health clinics offer the procedure at reduced cost, but this can only be done if a local gastroenterologist (a physician who specializes in treating stomach and intestinal disorders) is willing to donate his or her time.

Preparation

The purpose of preparation for sigmoidoscopy is to cleanse the lower bowel of stool so the physician can see the lining. Preparation begins 24 hours before the procedure, when the individual must begin a clear liquid diet. Preparation kits are available in drug stores. In normal preparation, about 20 hours before the exam, the patient begins taking a series of laxatives , which may be oral tablets or liquid. The individual must stop drinking four hours before the exam. An hour or two prior to the exam, the patient uses an enema or laxative suppository to finish cleansing the lower bowel.

Individuals need to be careful about medication before having sigmoidoscopy. They should not take aspirin, products containing aspirin, or ibuprofen products (Nuprin, Advil, or Motrin) for one week prior to the exam, because these medications can exacerbate bleeding during the procedure. They should not take any iron or vitamins with iron for one week prior to the exam, since iron can cause color changes in the bowel lining that interfere with the examination. They should take any routine prescription medication, but may need to stop certain medications; the physician should be consulted regarding routine prescriptions and their possible effect on sigmoidoscopy.

Aftercare

There is no specific aftercare necessary following sigmoidoscopy. If a biopsy was taken, a small amount of blood may appear in the next stool. Patients should be encouraged to pass gas following the procedure to relieve any bloating and cramping that may occur after the procedure. In addition, an infection may develop following sigmoidoscopy, and patients should be instructed to call their physician if a fever or pain in the abdomen develops over the few days after the procedure.

Complications

There is a slight risk of bleeding from the procedure. This risk is heightened in individuals whose blood does not clot well, either due to disease or medication, and in those with active inflammatory bowel disease. Rarely, trauma to the bowel or other organs can occur, resulting in an injury (perforation) that needs to be repaired or peritonitis, which must be treated with medication.

Results

A normal exam shows a smooth colon wall, with sufficient blood vessels for good blood flow.

For a cancer screening sigmoidoscopy, an abnormal result is one or more noncancerous or precancerous polyps, or clearly cancerous polyps. People with polyps have an increased risk of developing colorectal cancer in the future and may be required to undergo additional procedures, such as colonoscopy, or more frequent examinations.

Small polyps can be completely removed. Larger polyps may require the physician to remove a portion of the growth for laboratory biopsy. Depending on the laboratory results, the patient is then scheduled to have the polyp removed surgically, either as an "urgent" matter if it is cancerous or as an elective surgery within a few months if it is noncancerous.

In a diagnostic sigmoidoscopy, an abnormal result shows signs of active inflammatory bowel disease, either a thickening of the intestinal lining consistent with ulcerative colitis, or ulcerations or fissures consistent with Crohn's disease.

Health care team roles

Sigmoidoscopy is performed by an experienced family physician or gastroenterologist. Nurses or physician assistants may be present during the procedure to assist the physician and monitor the patient. Biopsy specimens taken during the sigmoidoscopy are analyzed in the clinical laboratory by a pathologist. Sigmoidoscopes and procedural accessories must be sterilized or disinfected by clinical staff trained in proper scope reprocessing techniques.

Resources

BOOKS

Beers, Mark H., and Robert Berkow, eds. Merck Manual of Diagnosis and Therapy. 17th ed. Merck Research Laboratories, 1999.

Fauci, Anthony S., et al., eds. Harrison's Principles of Internal Medicine. 14th ed. New York: McGraw-Hill, 1998.

PERIODICALS

Johnson, Brett Andrew. "Flexible Sigmoidoscopy: Screening for Colorectal Cancer." American Family Physician (January 15, 1999). <http://www.aafp.org/afp/990115ap/313.html>.

ORGANIZATIONS

Colorectal Cancer Network (CCNetwork). PO Box 182, Kensington, MD 20895-0182. (301) 879-1500. <http://www.colorectal-cancer.net>.

National Digestive Diseases Information Clearinghouse. 2 Information Way, Bethesda, MD 20892-3570. <http://www.niddk.nih.gov>.

Society of American Gastrointestinal Endoscopic Surgeons (SAGES). 2716 Ocean Park Boulevard, Suite 3000, Santa Monica, CA 90405. (310) 314-2404. <http://www.sages.org>.

Society of Gastroenterology Nurses and Associates Inc. 401 North Michigan Avenue, Chicago, IL 60611-4267. (800) 245-7462. <http://www.sgna.org>.

OTHER

Glaser, Vicki. "Colorectal Cancer Screening: New Directions, Evolving Guidelines." Patient Care. (February 28, 2001). <http://consumer.pdr.net/consumer>.

Jennifer E. Sisk, M.A.

Sigmoidoscopy

Definition

Sigmoidoscopy is a diagnostic and screening procedure in which a rigid or flexible tube with a camera on the end (a sigmoidoscope) is inserted into the anus to examine the rectum and lower colon (bowel) for bowel disease, cancer, precancerous conditions, or causes of bleeding and pain.

Purpose

Sigmoidoscopy is used most often in screening for colorectal cancer or to determine the cause of rectal bleeding. It is also used in diagnosis of inflammatory bowel disease, microscopic and ulcerative colitis, and Crohn's disease.

Cancer of the rectum and colon is the second most common cancer in the United States. About 155,000 cases are diagnosed annually. About 55,000-60,000 Americans die each year of colorectal cancer.

A number of studies have suggested, and it is now recommended by cancer authorities that people over 50 be screened for colorectal cancer using endoscopy every three to five years. Individuals with inflammatory bowel disease, such as Crohn's disease or ulcerative colitis, who are at increased risk for colorectal cancer, may begin their screenings at a younger age, depending on when their disease was diagnosed. Many physicians screen such patients more often than every three to five years. Screening should also be done in patients who have a family history of colon or rectal cancer or small growths in the colon (polyps).

Some physicians do this screening with a colonoscope, which allows them to see the entire colon. However, most physicians prefer sigmoidoscopy, which is less time consuming, less uncomfortable, and less costly.

Studies have shown that one quarter to one-third of all precancerous or small cancerous growths can be seen with a sigmoidoscope. About one-half are found with a 1 ft (30 cm) scope, and two-thirds to three-quarters can be seen using a 2 ft (60 cm) scope.

In some cases, the sigmoidoscope can be used therapeutically in conjunction with other equipment, such as electrosurgical devices, to remove polyps and other lesions found during the sigmoidoscopy.

Precautions

Sigmoidoscopy can usually be conducted in a physician's office or an outpatient clinic. However, some individuals should have the procedure done in a hospital day-surgery facility. Those with rectal bleeding may need full colonoscopy in a hospital setting. Patients whose blood does not clot well (possibly as a result of blood thinning medications) may need the procedure performed in a hospital setting as well.

Individuals with renal insufficiency or congestive heart failure need to be prepared in an alternative way, and must be carefully monitored during the procedure.

Sigmoidoscopy may be contraindicated in patients with severe active colitis or toxic megacolon (an extremely dilated colon). In general, patients on continuous ambulatory peritoneal dialysis are not candidates due to a high risk of developing intraperitoneal bleeding.

Description

Sigmoidoscopy may be performed using either a rigid or flexible sigmoidoscope, a thin tube with fiberoptics, electronics, a light source, and camera. The physician inserts the sigmoidoscope into the anus to examine the rectum (the first 1 ft/30 cm of the colon) and its interior walls. If a 2 ft/60 cm scope is used, the next portion of the colon can also be examined for any irregularities. The sigmoidoscope's camera is connected to a viewing monitor (television screen), so the rectum and colon are enlarged and viewed on a monitor. Images can then be recorded as still pictures for hard copy or the entire procedure can be videotaped.

If polyps, lesions, or other suspicious areas are found, the physician biopsies them for analysis. During the sigmoidoscopy, the physician may also use forceps, graspers, snares, or electrosurgical devices to remove polyps, lesions, or tumors.

The sigmoidoscopy procedure takes five to 20 minutes. Preparation begins one day before the procedure. There is some discomfort when the scope is inserted and throughout the procedure, similar to that experienced when a physician performs a rectal exam using a finger to test for occult blood in the stool (another major colorectal cancer screening test). The patient may also feel some minor cramping pain. There is rarely severe pain, except for individuals with active inflammatory bowel disease.

Private insurance plans almost always cover the $150 to $200 cost of sigmoidoscopy for screening in healthy individuals over 50, or for diagnostic purposes. Medicare covers the cost for diagnostic exams, and may cover the costs for screening exams. Medicaid varies by state, but does not cover the procedure in most states. Some community health clinics offer the procedure at reduced cost, but this can only be done if a local gastroenterologist (a physician who specializes in treating stomach and intestinal disorders) is willing to donate his or her time.

Preparation

The purpose of preparation for sigmoidoscopy is to cleanse the lower bowel of stool so the physician can see the lining. Preparation begins 24 hours before the procedure, when the individual must begin a clear liquid diet. Preparation kits are available in drug stores. In normal preparation, about 20 hours before the exam, the patient begins taking a series of laxatives, which may be oral tablets or liquid. The individual must stop drinking four hours before the exam. An hour or two prior to the exam, the patient uses an enema or laxative suppository to finish cleansing the lower bowel.

Individuals need to be careful about medication before having sigmoidoscopy. They should not take aspirin, products containing aspirin, or ibuprofen products (Nuprin, Advil, or Motrin) for one week prior to the exam, because these medications can exacerbate bleeding during the procedure. They should not take any iron or vitamins with iron for one week prior to the exam, since iron can cause color changes in the bowel lining that interfere with the examination. They should take any routine prescription medication, but may need to stop certain medications; the physician should be consulted regarding routine prescriptions and their possible effect on sigmoidoscopy.

Aftercare

There is no specific aftercare necessary following sigmoidoscopy. If a biopsy was taken, a small amount of blood may appear in the next stool. Patients should be encouraged to pass gas following the procedure to relieve any bloating and cramping that may occur after the procedure. In addition, an infection may develop following sigmoidoscopy, and patients should be instructed to call their physician if a fever or pain in the abdomen develops over the few days after the procedure.

Complications

There is a slight risk of bleeding from the procedure. This risk is heightened in individuals whose blood does not clot well, either due to disease or medication, and in those with active inflammatory bowel disease. Rarely, trauma to the bowel or other organs can occur, resulting in an injury (perforation) that needs to be repaired or peritonitis, which must be treated with medication.

Results

A normal exam shows a smooth colon wall, with sufficient blood vessels for good blood flow.

For a cancer screening sigmoidoscopy, an abnormal result is one or more noncancerous or precancerous polyps, or clearly cancerous polyps. People with polyps have an increased risk of developing colorectal cancer in the future and may be required to undergo additional procedures, such as colonoscopy, or more frequent examinations.

Small polyps can be completely removed. Larger polyps may require the physician to remove a portion of the growth for laboratory biopsy. Depending on the laboratory results, the patient is then scheduled to have the polyp removed surgically, either as an "urgent" matter if it is cancerous or as an elective surgery within a few months if it is noncancerous.

In a diagnostic sigmoidoscopy, an abnormal result shows signs of active inflammatory bowel disease, either a thickening of the intestinal lining consistent with ulcerative colitis, or ulcerations or fissures consistent with Crohn's disease.

Health care team roles

Sigmoidoscopy is performed by an experienced family physician or gastroenterologist. Nurses or physician assistants may be present during the procedure to assist the physician and monitor the patient. Biopsy specimens taken during the sigmoidoscopy are analyzed in the clinical laboratory by a pathologist. Sigmoidoscopes and procedural accessories must be sterilized or disinfected by clinical staff trained in proper scope reprocessing techniques.

KEY TERMS

Biopsy— The removal a small portion of tissue during sigmoidoscopy to perform laboratory tests to determine if the tissue is cancerous.

Colonoscopy— A diagnostic endoscopic procedure that uses a long flexible tube called a colonoscope to examine the inner lining of the entire colon; used for colorectal cancer screening and more thorough examination of the colon.

Colorectal cancer— Cancer of the large intestine, or colon, including the rectum (the last 16 in of the large intestine before the anus).

Congestive heart failure— Excess fluid accumulation in the lungs and surrounding tissues due to the weakness of the heart muscle and the inability to pump sufficiently.

Electrosurgical device— A medical device that uses electrical current to cauterize or coagulate tissue during surgical procedures, often used in conjunction with laparoscopy.

Inflammatory bowel disease— Ulcerative colitis or Crohn's disease; chronic conditions characterized by periods of diarrhea, bloating, abdominal cramps, and pain, sometimes accompanied by weight loss and malnutrition because of the inability to absorb nutrients.

Pathologist— A doctor who specializes in the diagnosis of disease by studying cells and tissues under a microscope.

Polyp— A small growth, usually not cancerous, but often precancerous when it appears in the colon.

Renal insufficiency— The inability of the kidneys to process fluid fast enough to flush the body of impurities.

Resources

BOOKS

Beers, Mark H., and Robert Berkow, eds. Merck Manual of Diagnosis and Therapy, 17th ed. Merck Research Laboratories, 1999.

Fauci, Anthony S., et al., eds. Harrison's Principles of Internal Medicine, 14th ed. New York: McGraw-Hill, 1998.

PERIODICALS

Johnson, Brett Andrew. "Flexible Sigmoidoscopy: Screening for Colorectal Cancer." American Family Physician (January 15, 1999). 〈http://www.aafp.org/afp/990115ap/313.html〉.

ORGANIZATIONS

Colorectal Cancer Network (CCNetwork). PO Box 182, Kensington, MD 20895-0182. (301) 879-1500. 〈http://www.colorectal-cancer.net〉.

National Digestive Diseases Information Clearinghouse. 2Information Way, Bethesda, MD 20892-3570. 〈http://www.niddk.nih.gov〉.

Society of American Gastrointestinal Endoscopic Surgeons(SAGES). 2716 Ocean Park Boulevard, Suite 3000, Santa Monica, CA 90405. (310) 314-2404. 〈http://www.sages.org〉.

Society of Gastroenterology Nurses and Associates Inc. 401North Michigan Avenue, Chicago, IL 60611-4267.(800) 245-7462. 〈http://www.sgna.org〉.

OTHER

Glaser, Vicki. "Colorectal Cancer Screening: NewDirections, Evolving Guidelines." Patient Care. (February 28, 2001). 〈http://consumer.pdr.net/consumer〉.

Sigmoidoscopy

Definition

Sigmoidoscopy is a procedure by which a doctor inserts either a short and rigid or slightly longer and flexible fiber-optic tube into the rectum to examine the lower portion of the large intestine (or bowel).

Purpose

Sigmoidoscopy is used most often in screening for colorectal cancer or to determine the cause of rectal bleeding. It is also used for the diagnosis of inflammatory bowel disease and other benign diseases of the lower intestine.

Cancer of the rectum and colon is the second most common cancer in the United States, and claims the lives of approximately 56,000 people annually. As a result, The American Cancer Society recommends that people age 50 and over be screened for colorectal cancer every five years. The screening includes a flexible sigmoidoscopy. Screening at an earlier age should be done on patients who have a family history of colon or rectal cancer, or small growths in the colon (polyps).

Individuals with inflammatory bowel disease (Crohn's colitis or ulcerative colitis ) are at increased risk for colorectal cancer and should begin their screenings at a younger age, and be screened more frequently. Many doctors screen such patients more often than every three to five years. Those with ulcerative colitis should be screened beginning 10 years after the onset of disease; those with Crohn's colitis beginning 15 years after the onset of disease.

Some doctors prefer to do this screening with a colonoscope, which allows them to see the entire colon (certain patients, such as those with Crohn's colitis or ulcerative colitis, must be screened with a colonoscope). However, compared with sigmoidoscopy, colonoscopy is a longer process, causes more discomfort, and is more costly.

Studies have indicated that about one-fourth of all precancerous or small cancerous growths in the colorectal region can be seen with a rigid sigmoidoscope. The longer, flexible version, which is the primary type of sigmoidoscope used in the screening process, can detect more than one-half of all growths in this region. This examination is usually performed in combination with a fecal occult blood test, in an effort to increase detection of polyps and cancers that lie beyond the scope's reach.

Precautions

Sigmoidoscopy can usually be conducted in a doctor's office or a health clinic. However, some individuals should have the procedure done in a hospital day surgery facility. These include patients with rectal bleeding, and patients whose blood does not clot well (possibly as a result of blood-thinning medications).

The exam is not always adequate. A 2004 study reported that among older patients and women, sigmoidoscopy is not always effective, particularly because insertion depth is not adequate. For unknown reasons, this is almost twice as true for women as for men.

Description

Most sigmoidoscopy is done with a flexible fiberoptic tube. The tube contains a light source and a camera lens. The doctor moves the sigmoidoscope up beyond the rectum (the first 1 ft/30 cm of the colon), examining the interior walls of the rectum. If a 2 ft/60 cm scope is used, the next portion of the colon can also be examined for any irregularities.

The procedure takes 20 to 30 minutes, during which time the patient will remain awake. Light sedation may be given to some patients. There is some discomfort (usually bloating and cramping) because air is injected into the bowel to widen the passage for the sigmoidoscope. Pain is rare except in individuals with active inflammatory bowel disease.

In a colorectal cancer screening, the doctor is looking for polyps or tumors. Studies have shown that over time, many polyps develop into cancerous lesions and tumors. Using instruments threaded through the fiber-optic tube, cancerous or precancerous polyps can either be removed or biopsied during the sigmoidoscopy. People who have cancerous polyps removed can be referred for full colonoscopy, or more frequent sigmoidoscopy, as necessary.

The doctor may also look for signs of ulcerative colitis, which include a loss of blood flow to the lining of the bowel, a thickening of the lining, and sometimes a discharge of blood and pus mixed with stool. The doctor can also look for Crohn's disease, which often appears as shallow or deep ulcerations, or erosions and fissures in the lining of the colon. In many cases, these signs appear in the first few centimeters of the colon above the rectum, and it is not necessary to do a full colonoscopic exam.

Private insurance plans often cover the cost of sigmoidoscopy for screening in healthy individuals over 50, or for diagnostic purposes. Medicare covers the cost for diagnostic exams, and may cover the costs for screening exams.

Preparation

The purpose of preparation for sigmoidoscopy is to clean the lower bowel of stool so that the doctor can see the lining. Many patients are required to consume only clear liquids on the day before the test, and to take two enemas on the morning of the procedure. The bowel is cleaner, however, if patients also take an oral laxative preparation of 1.5 oz phospho-soda the evening before the sigmoidoscopy.

Certain medications should be avoided for a week before having a sigmoidoscopy. These include:

• aspirin, or products containing aspirin
• ibuprofen products (Nuprin, Advil, or Motrin)
• iron or vitamins containing iron

Although most prescription medication can be taken as usual, patients should check with their doctor in advance.

Aftercare

Patients may feel mild cramping after the procedure that will improve after passing gas. Patients can resume their normal activities almost immediately.

Risks

There is a slight risk of bleeding from the procedure. This risk is heightened in individuals whose blood does not clot well, either due to disease or medication, and in those with active inflammatory bowel disease. The most serious complication of sigmoidoscopy is bowel perforation (tear). This complication is very rare, however, occurring only about once in every 7,500 procedures.

Normal results

A normal exam shows a smooth bowel wall with no evidence of inflammation, polyps or tumors.

Abnormal results

For a cancer screening sigmoidoscopy, an abnormal result involves one or more noncancerous or precancerous polyps or tumors. Patients showing polyps have an increased risk of developing colorectal cancer in the future.

Small polyps can be completely removed. Larger polyps or tumors usually require the doctor to remove a portion of the growth for diagnostic testing. Depending on the test results, the patient is then scheduled to have the growth removed surgically, either as an urgent matter if it is cancerous, or as an elective surgery within a few months if it is noncancerous.

In a diagnostic sigmoidoscopy, an abnormal result shows signs of active inflammatory bowel disease, either a thickening of the intestinal lining consistent with ulcerative colitis, or ulcerations or fissures consistent with Crohn's disease.

Sigmoidoscopy is a procedure most often used in screening for colorectal cancer and as a test in diagnosis of possible inflammatory bowel disease. As illustrated above, the physician can view the rectum and colon through a sigmoidoscope, a 12 inch (30 cm) or 24 inch (60 cm) flexible fiber-optic tube which contains a light source and a lens.

Resources

PERIODICALS

Johnson, Brett Andrew. "Flexible Sigmoidoscopy: Screening for Colorectal Cancer." American Family Physician March 15, 1999: 1537-46.

Manoucheri, Manoucher, et al. "Bowel Preparations for Flexible Sigmoidoscopy: Which Method Yields the Best Results?" The Journal of Family Practice 48, no. 4 (April, 1999): 272-4.

"Women are Twice as Likely as Men to Have an Inadequate Signoidoscopy Examination." Doctor February 5, 2004: 13.

OTHER

"Diagnostic Tests." The National Digestive Diseases Information Clearing house (National Institutes of Health). July 5, 2001. 〈http://www.niddk.nih.gov/health/digest/pubs/diagtest/index.htm〉.

"Overview: Colon and Rectum Cancer." The American Cancer Society. Jan. 20, 2005. http://www.cancer.org/docroot/CRI/content/CRI_2_2_1X_How_Many_People_Get_Colorectal_Cancer.asp?sitearea=.

KEY TERMS

Biopsy— A procedure where a piece of tissue is removed from a patient for diagnostic testing.

Colorectal cancer— Cancer of the large intestine, or colon, including the rectum (the last 16 in of the large intestine before the anus).

Inflammatory bowel disease— Ulcerative colitis or Crohn's colitis; chronic conditions characterized by periods of diarrhea, bloating, abdominal cramps, and pain, sometimes accompanied by weight loss and malnutrition because of the inability to absorb nutrients.

Polyp— A small growth that can be precancerous when it appears in the colon.