Diarrhea

Definition

Diarrhea is an increased frequency of stools or bowel movements (more than two or three per day) or liquidity of feces.

Description

In a normal adult, about 10 quarts (liters) of fluid waste leaves the stomach each day. All but a liter and a half is absorbed in the small intestine. The unabsorbed contents enter the large bowel or colon. Most of the fluid in the feces is reabsorbed by the large intestine. The fluid loss is about 100 milliliters each day. From a strictly medical perspective, diarrhea is defined as stool weight of more than 250 grams in 24 hours. In practice, the calculation of stool weights is restricted to persons with chronic diarrhea.

There are three broad classes that encompass most cases of diarrhea.

• Non-inflammatory diarrhea. This is described as a watery, non-bloody bowel movement that is associated with diffuse abdominal cramping, nausea, vomiting or bloating. The most common cause of non-inflammatory diarrhea is a bacterium that produces a toxin. Common examples of non-inflammatory bacteria include Escherichia coli, Staphylococcus aureus, Bacillus cereus and Clostridium perfringens. Some viruses and amoeba such as Giardia lamblia also cause non-inflammatory diarrhea. This diarrhea is typically mild but may be voluminous, involving large amounts of fluid (10 to 200 mL/kg/day). Such fluid loss results in dehydration and loss of electrolytes. There is usually no blood loss.
• Inflammatory diarrhea. This is usually characterized by the presence of fever and blood in the stool and is associated with left lower quadrant cramps, urgency, and tenesmus (anal spasms). Common causes of inflammatory diarrhea include infection with Campylobacter or Yersinia species or infection with some species of Escherichia coli. Diarrhea due to these pathogens tends to be less voluminous, less than 1 liter per day.
• Enteric fever. This is characterized by abdominal tenderness, confusion, prolonged high fever, prostration, and occasionally a rash. Common causes of enteric fever-related diarrhea include Salmonella typhi or Salmonella paratyphi. Multi-organ disease is frequently encountered.

Inflammatory diarrhea must be distinguished from ulcerative colitis.

Non-professionals may use the term diarrhea in reference to increased incidence of bowel movements, a sense of fecal urgency, increased stool liquidity, or fecal incontinence.

Causes and symptoms

Many cases of non-inflammatory diarrhea are caused by the organisms listed in the description section. The symptoms of diarrhea include nausea, weakness, and dehydration. After more that three of four episodes of diarrhea, lethargy develops. Occasionally, diffuse abdominal cramping is experienced.

Inflammatory diarrhea is characterized by fever, nausea, sweating (diaphoresis), and lower abdominal tenderness and cramping. Tenesmus is common but not always present. Weakness and dehydration are often present. Lethargy develops after three or four episodes of diarrhea.

Diarrhea that is associated with enteric illness will be accompanied by prolonged high fever, confusion, prostration, respiratory distress, and abdominal tenderness. Organisms that cause diarrhea have been described.

In babies and young children, dehydration is a significant problem that must be rapidly corrected to avoid severe consequences. Lethargy may be the most prominent symptom in these children.

In cases of chronic diarrhea, anemia may be present due to blood loss. Fatigue and lethargy are the most common observable symptoms. Laboratory tests can be used to confirm anemia due to blood loss. The same persons should be tested for ova and parasites in the stool.

Diagnosis

The causative agent of diarrhea may be recovered from a stool sample. Once recovered, it is grown in a laboratory, using standard culture techniques and procedures. Among persons with dysentery, the rate of positive identification of agents using bacterial culture is 60 to 75%. Persons with a recent history of possible exposure to amoeba, whether through travel or from sexual preference, should have a wet mount examination of stool for amoeba.

Laboratories should be alerted to the possibility of exposure to E. coli O157:H7 if exposure to improperly prepared food is suspected.

Stool should be examined for ova and parasites in persons with diarrhea that persists for more than 10 days. Three such examinations for ova and parasites should be performed.

Rectal swabs should be considered for persons suspected of having Neisseria gonorrhoeae, Chlamydia, or herpes simplex virus.

Sigmoidoscopy should be considered for persons with severe rectal pain, tenesmus, or rectal discharge. Sigmoidoscopy is often useful for differentiating infective diarrhea from ischemic or ulcerative colitis.

Treatment

There are four main elements of treatment: rehydration, diet, antidiarrheal agents, and antibiotic therapy.

Rehydration

Drinking fluids such as tea, sport drinks, fruit juices, and some mildly carbonated beverages, augmented with water, will rapidly replace fluid lost through diarrhea. Fluids should be consumed as rapidly as affected persons will tolerate them. Experts recommend fluid intake levels of 50-200 mL/ kg/day. Severely dehydrated individuals may require hospitalization and intravenous fluid therapy with lactated Ringer's solution. Persons who do not require hospitalization can make a similar solution that can be taken orally at home. Combine the following:

• 0.5 teaspoon salt
• 1.0 teaspoon baking soda
• 8 teaspoons water
• 8 ounces orange juice
• water to equal 1 quart

Diet

If persons with diarrhea consume adequate carbohydrates and fluids, most will avoid dehydration. Fluids that contain electrolytes are especially useful. Broth-based soups with crackers, sport drinks, and some soft drinks contain salt, potassium, sugar and bicarbonate. These substances are lost with diarrhea. The bowel should not be stressed during recovery from diarrhea. This can be accomplished by avoiding foods that are high in fiber, fatty foods, milk and dairy foods, alcohol, and caffeine. Eating relatively small meals on a frequent basis is helpful. Tea and fruit juices provide nourishment without stressing the digestive system.

Antidiarrheal agents

Persons with mild to moderate diarrhea usually benefit from antidiarrheal preparations. If diarrhea does not subside or worsens with the use of such agents, they should be discontinued and competent medical assistance sought. Preparations containing opioids (such as loperamide) should not be used by persons with bloody diarrhea or high fevers. In others, they will decrease stool liquidity, quantity, and tenesmus. The following preparations are generally useful:

• bismuth subsalicylate (Pepto-Bismol)
• loperamide (Imodium AD)

Antibiotic therapy

For the majority of persons with diarrhea, the condition is self-limiting. As such, antibiotic therapy is not indicated. For persons with moderate to severe diarrhea, antibiotic therapy may be helpful. Symptoms of bloody stools, fever and tenesmus are indications for the use of an antibiotic. The following are often used while awaiting the results of a stool culture. Because they are used without accurately identifying a causative agent for the diarrhea, their use is characterized as empirical.

• a fluoroquinolone such as ciprofloxacin
• erythromycin
• trimethoprim/sulfamethoxazole

Antibiotics are indicated for persons with so-called traveler's diarrhea or for diarrhea that is caused by cholera, shigellosis, or salmonellosis.

Prognosis

Most cases of diarrhea are self limiting. Once the causative agent or toxin is discharged with the fecal flow, recovery can begin. Over 90% of persons with acute diarrhea will recover fully with adequate rehydration or the use of antidiarrheal agents. Laboratory determination of the cause in such instances is infrequently required, since the cost is not justified. Laboratories identify approximately 3% of causative agents from stool cultures.

Laboratories will frequently examine stool samples for the presence of blood to differentiate inflammatory and non-inflammatory causes of diarrhea. After a diagnosis of inflammatory diarrhea has been made, stool cultures are needed to determine appropriate antimicrobial therapy.

Hospitalization for diarrhea is uncommon but warranted for severe diarrhea. Babies and older persons are at increased risk for adverse outcomes, including death, from diarrhea.

Each day, more than 1,700 babies around the world die from diarrheal diseases. Most of these are due to a lack of potable drinking water. With adequate hydration using non-contaminated water, most of these deaths could be prevented. Without clean drinking water, their prognosis is often poor.

Health care team roles

Diarrhea is usually diagnosed by someone other than a professional member of a health care team. Treatment is often provided by the same person. When professional advice is sought, a family physician, internist, pediatrician, physician's assistant or nurse practitioner is most likely to be consulted. A laboratory technician may process stool samples and identify a causative agent. In unusual circumstances, a pathologist may be called upon to identify a causative pathogen. A specialist in infectious diseases may provide assistance. Epidemiologists and sanitarians have an interest in diarrhea outbreaks or clusters of cases. Health officers may be called upon to take preventive measures if food sources, public restaurants or day care centers are shown to be the causes of a diarrhea outbreak.

Prevention

Handwashing and personal hygiene are critical methods for preventing diarrhea. Adequate hand-washing alone will prevent a majority of diarrhea cases.

Adequate sanitation and attention to cleanliness are the best ways to prevent outbreaks of diarrhea disease. Persons handling food must always wash their hands before touching any food. Food, especially poultry and shellfish, must be stored at appropriate temperatures and thoroughly washed before being prepared for consumption.

Food must be properly prepared and held or stored at proper temperatures. Prior to cooking, foods should be kept at temperatures below 40°F (4.4°C). During cooking, the internal temperature of foods should exceed 160°F (71°C) to ensure the destruction of pathogens. While being served, food should be held at temperatures between 40 and 140°F (4.4 and 60°C). The total time that food should be allowed to remain within these temperatures is four hours. After four hours total time, including original serving and subsequent reheating, the food should be discarded. Foods that contain eggs, such as mayonnaise and salads, should be kept cold and protected from heat and sunlight.

Day care facilities must be constantly cleaned and disinfected. Employees who change diapers must wash their hands before returning to work.

Persons should drink only potable water. Water that is used for washing dishes or personal uses such as tooth brushing should also be boiled before use if the source of the water is not assured to be potable and safe.

KEY TERMS

Diaphoresis— An alternative for sweating.

Incontinence— The inability to voluntarily control elimination of bodily wastes.

Inflammation— A physiological response to stress on the body that is characterized by redness, tenderness, increased temperature, swelling and decrease or loss of function.

Ova— Eggs.

Sigmoidoscopy— Procedure to visualize the interior of the colon. A flexible tube is inserted in the anus. An operator looks into the colon that is illuminated by a light at the end of the tube.

Stool— An alternative name for feces.

Tenesmus— A feeling that a bowel movement is imminent.

Resources

BOOKS

Bass, Doesey M. "Rotavirus and other agents of viral gastroenteritis." In Nelson Textbook of Pediatrics, 16th ed. Edited by Richard E. Behrman et al., Philadelphia: Saunders, 2000, 996-998.

Blaser, Martin J. "Infections due to Campylobacter and related species." In Harrison's Principles of Internal Medicine, 14th ed. Edited by Anthony S. Fauci, et al. New York: McGraw-Hill, 1998, 960-962.

Butler, Thomas. "Shigellosis." In Cecil Textbook of Medicine, 21st ed. Edited by Goldman, Lee and J. Claude Bennett. Philadelphia: W.B. Saunders, 2000, 1685-1687.

Cleary, Thomas G. "Salmonella." In Nelson Textbook of Pediatrics, 16th ed. Edited by Richard E. Behrman et al., Philadelphia: Saunders, 2000, 842-848.

Ghishan, Fayez K. "Chronic diarrhea." In Nelson Textbook of Pediatrics, 16th ed. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2000, 1171-1176.

Gomez, Henry F. and Thomas G. Cleary. "Shigella." In Nelson Textbook of Pediatrics, 16th ed. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2000, 848-850.

Greenberg, Harry B. "Viral gastroenteritis." In Harrison's Principles of Internal Medicine, 14th ed. Edited by Anthony S. Fauci, et al. New York: McGraw-Hill, 1998, 1116-1118.

Guerrant, Richard L. "Campylobacter enteritis." In Cecil Textbook of Medicine, 21st ed. Edited by Goldman, Lee and J. Claude Bennett. Philadelphia: W.B. Saunders, 2000, 1687-1690.

Kapikian, Albert Z. "Viral gastroenteritis." In Cecil Textbook of Medicine, 21st ed. Edited by Goldman, Lee and J. Claude Bennett. Philadelphia: W.B. Saunders, 2000, 1835-1840.

Kaye, Donald. "Salmonella infections other than typhoid fever." In Cecil Textbook of Medicine, 21st ed. Edited by Goldman, Lee and J. Claude Bennett. Philadelphia: W.B. Saunders, 2000, 1683-1685.

Keusch, Gerald T. "Salmonellosis." In Harrison's Principles of Internal Medicine, 14th ed. Edited by Anthony S. Fauci, et al. New York: McGraw-Hill, 1998, 950-957.

Keusch, Gerald T. "Schigellosis." In Harrison's Principles of Internal Medicine, 14th ed. Edited by Anthony S. Fauci, et al. New York: McGraw-Hill, 1998, 957-960.

Pearson, Richard D. "Advice to travelers." In Cecil Textbook of Medicine, 21st ed. Edited by Goldman, Lee and J. Claude Bennett. Philadelphia: W.B. Saunders, 2000, 1586-1590.

Powell, Don W. "Approach to the patient with diarrhea." In Cecil Textbook of Medicine, 21st ed. Edited by Goldman, Lee and J. Claude Bennett. Philadelphia: W.B. Saunders, 2000, 702-712.

Ratnaike, Ranjit N. Diarrhoea and Constipation in Geriatric Practice. Cambridge (UK): Cambridge University Press, 1999.

Sack, R. Bradley. "The diarrhea of travellers." In Cecil Textbook of Medicine, 21st ed. Edited by Goldman, Lee and J. Claude Bennett. Philadelphia: W.B. Saunders, 2000, 1696-1697.

Weissman, Sharon B., and Robert A. Salata. "Amebiasis." In Nelson Textbook of Pediatrics, 16th ed. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2000, 1035-1036.

PERIODICALS

Ahmed F., M. Ansaruzzaman, E. Haque, M. R. Rao, J. D. Clemens. "Epidemiology of postshigellosis persistent diarrhea in young children." Pediatric Infectious Disease Journal vol. 20 no. 5 (2001): 525-530.

Fontaine O., C. Newton. "A revolution in the management of diarrhoea." Bulletin of the World Health Organization vol. 79 no. 5 (2001): 471-472.

Holt P. R. "Diarrhea and malabsorption in the elderly." Gastroenterology Clinics of North America vol. 30 no. 2 (2001): 427-444.

Mahalanabis D., A. B. Choudhuri, N. G. Bagchi, A. K. Bhattacharya, and T. W. Simpson. "Oral fluid therapy of cholera among Bangladesh refugees." Bulletin of the World Health Organization vol. 79 no. 5 (2001): 473-479.

Mangala S., D. Gopinath, N. S. Narasimhamurthy, and C. Shivaram. "Impact of educational intervention on knowledge of mothers regarding home management of diarrhoea." Indian Journal of Pediatrics vol. 68 no. 5 (2001): 393-397.

Nakajima H., T. Nakagomi, T. Kamisawa, N. Sakaki, K. Muramoto, T. Mikami, H. Nara, and O. Nakagomi. "Winter seasonality and rotavirus diarrhoea in adults." Lancet vol. 357 no. 9272 (2001): 1950-1953.

Okhuysen, P. C. "Traveler's diarrhea due to intestinal protozoa." Clinical Infectious Disease vol. 33 no. 1 (2001): 110-114.

Scheidler M.D., R. A. Giannella. "Practical management of acute diarrhea." Hospital Practice vol. 36 no. 7 (2001): 49-56.

Spencer, D.C. "Are antibiotics effective for travelers' diarrhea?" Journal of Family Practice vol. 50 no. 6 (2001): 495-496.

ORGANIZATIONS

American Academy of Emergency Medicine, 611 East Wells Street, Milwaukee, WI 53202. (800) 884-2236. Fax: (414) 276-3349. 〈http://www.aaem.org〉.

American College of Gastroenterology, 4900 B South 31st Street, Arlington VA 22206. (703) 820-7400. Fax: (703) 931-4520. 〈http://www.acg.gi.org〉.

American College of Osteopathic Emergency Physicians, 142 E. Ontario Street, Suite 550, Chicago, IL 60611. (312) 587-3709 or (800) 521-3709. Fax: (312) 587-9951. 〈http://www.acoep.org〉.

Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333. (404) 639-3534 or (800) 311-3435. 〈http://www.cdc.gov/ncidod/eid/vol7no1/brown.htm〉. 〈http://www.cdc.gov/netinfo.htm〉.

College of American Pathologists, 325 Waukegan Road, Northfield, IL 60093. (800) 323-4040. 〈http://www.cap.org〉.

Pan American Health Organization, 525 Twenty-third Street, NW, Washington, D.C. 20037. (202) 974-3000. Fax: (202) 974-3663. 〈http://www.paho.org〉. [email protected].

World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland. +41 (22) 791 4140. Fax: +41 (22) 791 4268. 〈http://www.who.int/gtb〉. [email protected].

OTHER

American Academy of Family Physicians. 〈http://familydoctor.org/healthfacts/196〉.

Boston University. 〈http://www.bu.edu/cohis/infxns/common/diarrhea/diarrhea.htm〉.

Centers for Disease Control and Prevention. 〈http://www.cdc.gov/travel/foodwatr.htm〉.

National Digestive Diseases Clearinghouse. 〈http://www.niddk.nih.gov/health/digest/pubs/diarrhea/diarrhea.htm〉.

National Library of Medicine. 〈http://www.nlm.nih.gov/medlineplus/diarrhea.html〉 and 〈http://www.nlm.nih.gov/medlineplus/ency/article/003126.htm〉.

Quick Care. 〈http://www.quickcare.org/gast/diarrhea.html〉.

Rehydration Project. 〈http://www.rehydrate.org〉.