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Diseases & Conditions

Crohn's Disease

Crohn's disease is a chronic illness in which the intestine (bowel) becomes inflamed and ulcerated (marked with sores). Along with ulcerative colitis, Crohn’s disease is part of a group of diseases known as inflammatory bowel disease (IBD).

Crohn’s disease most commonly affects the lower part of the small intestine (ileum), although it can occur in any part of the large or small intestine, stomach, esophagus or even the mouth. It can occur at any age, but it is most common between the ages of 15 and 30.

Crohn's disease can disrupt the normal function of the bowel in a number of ways. The tissue may:

  • Swell, thicken, or form scar tissue leading to blockage of the passageway inside the bowel
  • Develop ulcers that can involve the deep layers of the bowel wall
  • Lose its ability to absorb nutrients from digested foods (malabsorption)
  • Develop abnormal passageways (fistulas) from one part of the bowel to another part of the bowel, or from the bowel to nearby tissues such as the bladder or vagina, even skin.

Symptoms of Crohn's Disease

People with Crohn's disease experience periods of severe symptoms followed by periods of remission that can last for weeks or years. Unfortunately there is no way to determine when a remission will occur or when symptoms will return. The symptoms of Crohn's disease depend on where the disease occurs in the bowel and its severity. In general, symptoms at times include:

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  • Chronic diarrhea
  • Rectal bleeding
  • Weight loss
  • Fever
  • Abdominal pain and tenderness (often on the right side of the lower abdomen)
  • Feeling of a mass or fullness in the lower, right abdomen
  • Delayed development and stunted growth (in children)

Other symptoms can develop, depending on complications related to the disease. For example, a person with a fistula (abnormal passage way) in the rectal area may have pain and discharge around the rectum. Other complications from Crohn’s disease include:

Causes of Crohn's Disease

The cause of Crohn's disease is unknown. It is believed to be multifactorial that causes an abnormal response of the immune system in the gastrointestinal tract. Genetic predisposition has been found to play a role in the disease process. There are over 100 genes found to be associated with Crohn’s disease, among them, only about 30% of overall susceptibility attributable to NOD2/CARD 15 which is relatively well studied. Abnormalities in the gene are found in up to 20% of general population with low penetrance. Therefore, the screening for gene mutation is not sufficient nor necessary for Crohn’s disease.

First-degree relatives of patients with IBD are about 3 to 20 times more likely to develop the disease than the general population. Having a sibling with CD can increase the risk of developing CD by 30 times compared with the general population. Offspring with single parent having Crohn’s disease and Jewish people of European descent also have a greater risk for developing the disease.

Diagnosing Crohn's Disease

A number of tests are used to distinguish Crohn's disease from other gastrointestinal conditions. First, your physician will review your medical history. This information is helpful because Crohn's disease is more common in people who have a first-degree relative (mother, father, sister or brother) with IBD. After the physical examination is complete, the following tests may be ordered:

  • Endoscopy (such as colonoscopy or sigmoidoscopy): During this procedure, a flexible, lighted tube (called an endoscope) is inserted into the rectum and used to view the inside of the rectum and colon. (Colonoscopy shows a greater portion of the colon than sigmoidoscopy.) A small sample of tissue may also be taken for testing (biopsy).
  • Blood tests: When testing the blood, the doctor will look for signs of anemia, or a high white blood cell count, which will indicate inflammation or infection somewhere in the body.
  • Barium X-ray (barium enema or small bowel series): During these procedures, X-rays are taken of either the upper or lower intestine. Barium coats the lining of the small intestine and colon, and shows up white on an X-ray. This characteristic enables doctors to view any abnormalities.
  • CT scan: X-ray of the abdomen that highlights the extent and severity of bowel inflammation, as well as identifying lesions in other organs.

Treating and Managing Crohn's Disease

Treatment for Crohn's disease is determined by the severity and location of the disease. Because the disease can sometimes go into remission on its own, it is not always possible to determine whether a specific treatment has been effective. When Crohn’s disease is active, treatment is aimed at controlling inflammation, correcting nutritional deficiencies and relieving symptoms such as pain, diarrhea and fever.

Medications are generally the first step in treating Crohn’s disease. Some of these medications include anti-inflammatories, antibiotics, corticosteroids, antidiarrheals and immune suppressing medications. For those patients experiencing nutritional deficiencies, supplements are often prescribed.

Even though it cannot cure Crohn’s disease, surgery is sometimes needed for patients whose symptoms do not respond to medications. Surgery can be performed to correct perforations, blockages or bleeding in the intestine. Unfortunately, Crohn’s disease often returns to the area next to where the inflamed part was removed. It is therefore important that you discuss with your doctor all possible options before deciding upon surgery.

In managing Crohn’s disease it is very important to maintain a healthy lifestyle, even when the disease goes into remission for long periods of time. This can be accomplished by exercising regularly and eating a healthy diet. Abstaining from smoking can also help prevent symptoms from recurring. Studies have shown that smokers are at a higher risk of developing Crohn’s disease than non-smokers and that smokers with Crohn’s disease tend to have a more severe course than non-smokers with Crohn’s disease. People with Crohn’s disease are usually able to lead healthy and active lifestyles.

Like many other disorders, understanding and education about Crohn’s disease is the most important tool with which to manage and prevent complications. The following organizations can provide more information about Crohn’s disease:

Crohn’s and Colitis Foundation of America, Inc.
386 Park Avenue South, 17th Floor
New York, NY 10016
(800) 932-2423

National Institute of Diabetes and Digestive and Kidney Diseases
2 Information Way
Bethesda, MD 20892


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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 8/23/2012...#9357