Inflammatory bowel disease (IBD) refers to a group of inflammatory disorders mostly of the large intestine including ulcerative colitis and Crohn’s disease, that cause the intestines to become inflamed.

Description

Although ulcerative colitis and Crohn’s disease have some features in common, there are some important differences.

Crohn’s disease

Crohn’s disease (CD) can involve ongoing (chronic) inflammation of the gastrointestinal tract, from the mouth to the anus, with ulceration and formation of fistulas and perianal abscesses. Five types are recognized, depending on the affected region:

Ileocolitis. This is the most common form, it affects the lowest part of the small intestine (ileum) and the large intestine (colon).
Ileitis. This type affects the ileum.
Gastroduodenal CD. This type causes inflammation in the stomach and first part of the small intestine, called the duodenum.
Jejunoileitis. This type causes spotty inflammation in the top half of the small intestine (jejunum).
Granulomatous CD colitis. This type affects the large intestine.

Ulcerative colitis

Ulcerative colitis typically involves continuous inflammation from the rectum to the entire colon. The disease usually begins in the rectal area and may eventually spread to the entire large intestine. Repeated inflammation thickens the wall of the intestine and rectum with scar tissue.

Demographics

More than 600,000 Americans are diagnosed every year with some type of inflammatory bowel disease. Ulcerative colitis may affect any age group, although there are peaks at ages 15 to 30 and at ages 50 to 70. Crohn’s disease may occur at any age, but it commonly affects persons between ages 15 and 35. Risk factors include a family history of Crohn’s disease, Jewish ancestry, and smoking. Men and women appear to be at equal risk of developing IBD. According to the Crohn’s and Colitis Foundation of America, two- thirds to three-quarters of patients with Crohn’s disease will need bowel surgery at some time.

Causes and symptoms

The exact causes of IBD are unknown. The disease may be caused by a germ or by an immune system problem. It is known that IBD is not contagious and it seems to be hereditary. In the case of ulcerative colitis, symptoms vary in severity and may start gradually or suddenly. They usually include all or some of the following:

Abdominal pain and cramps that usually disappear after a bowel movement;
Constipation, difficulty passing stool;
Diarrhea. It can be intermittent to very frequent;
Fever;
Gastrointestinal bleeding;
Gurgling or splashing sound heard over the intestine;
Nausea and vomiting;
Pain in the joints;
Undesired weight loss

The exact cause of Crohn’s disease is also unknown, but it has been linked to a problem with the body’s immune system (autoimmune disease). The immune system helps protect the body from harmful foreign substances and pathogens. But in patients with Crohn’s disease, the immune system can no distinguish between the body’s own cells and foreign invaders. The result is an overactive immune response that leads to chronic inflammation. Since Crohn’s Disease can affect any part of the gastrointestinal tract, symptoms can vary greatly between affected individuals. The following may be observed:

Abdominal fullness and gas
Abdominal pain and cramps
Blood clotting problems
Constipation
Diarrhea. (It is usually persistent and watery)
Eye inflammation
Fatigue
Fever
Fistulas
Foul-smelling stools
Gastrointestinal bleeding
Gurgling or splashing sound heard over the intestine

KEY TERMS

Abdomen —Part of the body that extends from the chest to the groin.

Anal fissures —Splits or cracks in the lining of the anus resulting from the passage of very hard or watery stools.

Autoimmune disorder —Autoimmune disorders are conditions in which a person’s immune system attacks the body’s own cells, causing tissue destruction.

Cecum —The pouch-like start of the large intestine that links it to the small intestine.

Colon —Part of the large intestine, located in the abdominal cavity. It consists of the ascending colon, the transverse colon, the descending colon, and the sigmoid colon.

Diverticulitis —Inflammation of the small pouches (diverticula) that can form in the weakened muscular wall of the large intestine.

Duodenum —The first section of the small intestine, extending from the stomach to the jejunum, the next section of the small intestine.

Fistula —Abnormal, usually ulcerous duct between two internal organs or between an internal organ and the skin. When open at only one end it is called an incomplete fistula or sinus. The most common sites of fistula are the rectum and the urinary organs.

Gastrointestinal tract (GI tract) —The tube connecting and including the organs and paths responsible for processing food in the body. These are the mouth, the esophagus, the stomach, the liver, the gallbladder, the pancreas, the small intestine, the large intestine, and the rectum.

Ileum —The last section of the small intestine located between the jejunum and the large intestine.

Jejunum —The section of the small intestine located between the duodenum and the ileum.

Immune system —The integrated body system of organs, tissues, cells, and cell products such as antibodies that protects the body from foreign organisms or substances.

Large intestine —The terminal part of the digestive system, site of water recycling, nutrient absorption, and waste processing located in the abdominal cavity. It consists of the caecum, the colon, and the rectum.

Mucosa —Lining of the digestive tract. In the mouth, stomach, and small intestine, the mucosa contains glands that produce juices to digest food.

Pancreas —The pancreas is a flat, glandular organ lying below the stomach. It secretes the hormones insulin and glucagon that control blood sugar levels and also secretes pancreatic enzymes in the small intestine for the breakdown of fats and proteins.

Perianal abscess —Abscess that can occur when the tiny anal glands that open on the inside of the anus become blocked and infected by bacteria. When pus develops, an abscess forms.

Prebiotics —Substances that help manage bacteria. Two principal types commonly used are the manna-noligosaccharides (MOS) that bind potentially harmful bacteria in the gut and allow beneficial bacteria to dominate, and fructanoligosaccharides (FOS) that deliver fructans into the fore gut to ’feed’ the acid producing bacteria.

Probiotics —Probiotics are dietary supplements containing potentially beneficial bacteria or yeast.

Rectum —Short, muscular tube that forms the lowest portion of the large intestine and connects it to the anus.

Ulceration —Formation of ulcers on a mucous membrane accompanied by pus and necrosis of surrounding tissue.

Kidney stones
Loss of appetite
Pain in the joints
Rectal bleeding and bloody stools
Skin rash
Swollen gums
Undesired weight loss

Diagnosis

Based on a careful history of symptoms, the examining physician will be able to distinguish between Crohn’s disease and ulcerative colitis. But diagnosis can be troublesome because other diseases have IBSlike symptoms. For example, Crohn’s disease is commonly misdiagnosed as celiac disease, or diverticulitis. This is because it can affect various regions of the gastrointestinal tract. Physicians accordingly use additional tests such as:

Barium enema before x rays. In this test, also called a “lower gastrointestinal (GI) series”, an enema tube is inserted into the patient’s rectum and a barium solution is allowed to flow in to improve the contrast of the x rays.
Colonoscopy. Test that allows the physician to look inside the colon using a colonoscope, a long, flexible tube that has a miniaturized color-TV camera at one end. It is inserted through the rectum into the colon, and provides a view of the lining of the lower digestive tract on a television monitor.
Complete blood count (CBC) test. This test measures the number of red and white blood cells, the amount of hemoglobin in the blood, the fraction of the blood composed of red blood cells (hematocrit), and the size of the red blood cells.
C-reactive protein (CRP). CRP is a test that measures the amount of a protein in the blood that signals acute inflammation.
Endoscopic ultrasound (EUS). Technique that uses sound waves to create a picture of the inside of the body. It uses a special endoscope that has an ultrasound device at the tip. It is placed in the gastrointestinal tract, close to the area of interest.
Esophagogastroduodenoscopy (EGD). EGD is a technique used to look inside the esophagus, stomach, and duodenum. It uses an endoscope to investigate swallowing difficulties, nausea, vomiting, reflux, bleeding, indigestion, abdominal pain, or chest pain.
Flexible sigmoidoscopy. Technique that allows to look at the inside of the large intestine from the rectum through the last part of the colon, called the sigmoid colon.
Sedimentation rate (ESR). This test draws blood from a vein, usually from the inside of the elbow or the back of the hand. It measures the distance that red blood cells settle in unclotted blood toward the bottom of a specially marked test tube.
Stool guaiac. This test finds hidden (occult) blood in the stool.

Treatment

The primary goal of treatment is to control inflammation and reduce the symptoms of pain, diarrhea, and bleeding when present. Many types of medicine can reduce inflammation, including antiinflammatory drugs such as sulfasalazine (Azulfidine), corticosteroids such as prednisone, and immune system suppressors such as azathioprine (Imuran) and mercaptopurine (Purinethol). An antibiotic, such as metronidazole (Flagyl), may also be helpful for destroying germs in the intestines, especially for Crohn’s disease. Anti-diarrheal medication, laxatives, and pain relievers may also be prescribed. If symptoms are severe, such as diarrhea, fever or vomiting, hospitalization may be required to administer intravenous fluids and medicines.

In the case of severe ulcerative colitis that can not be helped by medications, a type of surgery called bowel resection may be performed to remove a damaged part of the intestine or to drain an abscess. If a part of the bowel is removed, a procedure is done to connect the remaining two ends of the bowel (anastomosis). In very severe cases, removal of the entire large intestine (colectomy) is required. Bowel resections may also be performed for Crohn’s disease patients.

Nutrition/Dietetic concerns

An exact IBD diet does not actually exist, since no specific diet has been shown to improve or worsen bowel inflammation. However, eating a diet sufficient in energy and balanced in macronutrients and essential micronutrients is important to avoid malnutrition and weight loss. Foods that worsen diarrhea should also be avoided. People who have blockage of the intestines may need to avoid raw fruits and vegetables. Those who have difficulty digesting lactose (lactose intolerance) also need to avoid milk products. The following guidelines, upon approval by the treating physician or a registered dietician, can help prevent malnutrition and extreme weight loss:

Drinking plenty of fluids (8-10 servings daily) helps to keep body hydrated and prevent constipation
A daily multivitamin and mineral supplement may be indicated to replace lost nutrients
Eating a high fiber diet can help when IBD is under control. High fiber foods include grains (whole grain breads, buns, bagels, muffins, bran cereals, Corn bran, shredded whole wheat, 100% bran and fiber cereal, cooked cereal such as oat bran, whole-wheat pastas, whole grains such as barley, popcorn, corn and brown rice), fruits (dried fruits such as apricots, dates, prunes and raisins, berries such as blackberries, blueberries, raspberries and strawberries, oranges, apple with skin, avocado, kiwi, mango and pear), vegetables (broccoli, spinach, green peas and other dark green leafy vegetables, dried peas and beans such as kidney beans, lima beans, black-eyed beans, chick peas and lentils), and nuts and seeds (almonds, whole flaxseed and soynuts)
During an IBD attack, however, a low residue diet may help give the bowel a rest and minimize symptoms. A low residue diet includes grains that are not whole (enriched refined white bread, buns, bagels, english muffins, plain cereals such as Cornflakes, cream of wheat, Rice Krispies, or Special K, arrowroot cookies, tea biscuits, soda crackers, plain melba toast, white rice, refined pasta and noodles), fruits, peeled when necessary (fruit juices except prune juice, applesauce, apricots, cantaloupe, canned fruit cocktail, grapes, melon, peaches), but avoiding raw and dried fruits, raisins and berries. As for vegetables, they may include vegetable juices, potatoes (without skin), well-cooked vegetables such as alfalfa sprouts, beets, green or yellow beans, carrots, celery, cucumber, eggplant, lettuce, mushrooms, green or red peppers, squash, zucchini, while avoiding vegetables from the cabbage family such as broccoli, cauliflower, brussels sprouts, cabbage, and kale. Meats should be well-cooked, and tender, fish and eggs fresh. Beans, lentils, all nuts and seeds, as well as foods that may contain seeds (such as yogurt) should be avoided.
Lactose-containing foods such as dairy products should be avoided if lactose intolerance is present. Calcium-fortified soy milk can be substituted.
During flare-ups, small frequent meals may be preferable. A high protein diet with lean meats, fish and eggs, may also help relieve symptoms.
Caffeine, alcohol and sorbitol should be restricted, as these may exacerbate IBD symptoms. Sorbitol is an artificial sweetener present in many brands of chocolate, snacks and candy.
Gas-producing foods such as cabbage-family vegetables (broccoli, cabbage, cauliflower and brussels sprouts), dried peas and lentils, onions and chives, hot or chilli peppers and carbonated drinks should be restricted.
Fat intake should be reduced if part of the intestine has been surgically removed, because high fat foods usually cause diarrhea and gas for such patients.
Some studies suggest that fish oil and flax seed oil may be helpful in managing IBD. Recent studies also suggest a role in the healing process for probiotics and prebiotics such as psyllium, a soluble fiber that comes from a plant called Plantago afra. These may also be helpful in helping the recovery of the intestines.

Therapy

The management of IBD depends on the type diagnosed and pharmacologic and other therapies are accordingly tailored to individual cases, depending on severity and patient history. This also requires careful selection of therapeutic agents based on symptom severity and drug side effects. Since IBD is a chronic illness with an important and unpredictable impact on a person’s life, an effective therapy usually requires much more than the simple treatment of symptoms. Patient cooperation is crucial for improvement, as dietary and lifestyle changes have been shown to be beneficial. Whatever the symptoms, patients also need to get enough rest while learning to manage the stress in their lives, as intestinal problems tend to get worse in overly stressed persons. The Crohn’s and Colitis Foundation of America (CCFA) can provide patient information on IBD and support groups that can often help with the stress of dealing with IBD, with useful tips for finding the best treatment and coping with the disease.

Prognosis

The outcome of the ulcerative colitis is variable. It may be dormant and then worsen over a period of years, or progress quickly. The risk of colon cancer increases after ulcerative colitis is diagnosed.

There is no cure for Crohn’s disease, but it is not a deadly illness. Periods of improvement are often followed by flare-ups of symptoms. People with Crohn’s disease have an increased risk of small bowel or color-ectal cancer.

Prevention

IBD is not considered preventable, and once it occurs it is a lifelong disease. However, it is possible to prevent IBD secondary complications. For instance, depression is a common problem in people diagnosed with IBD. This may be the result of the underlying diagnosis or the medications used to treat these chronic inflammatory processes. Specific information is available for patients and their families about ways to manage their condition and treatment and prevent themselves against becoming depressed.

Resources

BOOKS

Sklar, J. The First Year: Crohn’s Disease and Ulcerative Colitis: An Essential Guide for the Newly Diagnosed. New York, NY: Marlowe and Company, 2007.

Dalessandro, T. M. What to Eat with IBD: A Comprehensive Nutrition and Recipe Guide for Crohn’s Disease and Ulcerative Colitis. New York, NY: iUniverse (Barnes and Noble), 2006.

Zonderman, J., Vender, R. S. Understanding Crohn Disease and Ulcerative Colitis. Jackson, MS: University Press of Mississippi, 2006.

Targan, R. T., Shanahan, F., Karp, L. C., eds. Inflammatory Bowel Disease: From Bench to Bedside. New York, NY: Springer, 2005.

Kane, S. V., Dubinsky, M. C., eds. Pocket Guide to Inflammatory Bowel Disease. Cambridge, UK: Cambridge University Press, 2005.

Scala, J. The New Eating Right for a Bad Gut : The Complete Nutritional Guide to Ileitis, Colitis, Crohn’s Disease, and Inflammatory Bowel Disease. London, UK: Plume Books (Penguin Group), 2000.

Hanauer, S. B. Inflammatory Bowel Disease: A Guide for Patients and Their Families. Philadelphia, PA: Lippin-cott Williams & Wilkins, 1999.

ORGANIZATIONS

American Gastroenterological Association. 930 Del Ray Avenue, Bethesda, MD 20814. (301)654-2055. <www.gastro.org>.

Cleveland Clinic Foundation. 9500 Euclid Ave. NA31 Cleveland, OH 44195. Department of Patient Education and Health Information: 1-800-223-2273). <www.clevelandclinic.org/health/>.

Crohn’s and Colitis Foundation of America. 386 Park Avenue South, 17th Floor, New York, NY 10016. 1-800-932-2423. <www.ccfa.org>.

International Foundation for Functional Gastrointestinal Disorders Inc. P.O. Box 170864, Milwaukee, WI 53217-8076. 1-888-964-2001. <www.iffgd.org>.

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health. 31 Center Drive, MSC 2560, Bethesda, MD 20892-2560. 1-800-891-5389. <digestive.niddk.nih.gov/ddiseases/pubs/facts/index.htm>.

Monique Laberge, Ph.D.

The Gale Encyclopedia of Diets: A Guide to Health and Nutrition