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Crohn's Disease


Crohn's disease is a type of inflammatory bowel disease (IBD). It can cause inflammation along any part of the digestive tract – from the mouth to the anus – but most commonly affects the last part of the small intestine, called the ileum, and the large intestine, including the rectum. It's considered a chronic condition because it may recur throughout a person's lifetime, with periods that are free of symptoms. Unfortunately, there is no way to predict when symptoms will return.

Most people with Crohn's disease are diagnosed before the age of 30, although the condition can occur in young children and in adults well past middle age. Men and women are equally affected, and people living in northern climates have a higher incidence. The condition can be inherited and is common in some families. About 12 percent of people with Crohn's disease have a close relative who also has the disease or has the other main type of IBD, ulcerative colitis. The cause of Crohn's disease is unknown. However, the primary trigger of the disease is believed to be the immune system's response to certain viruses and bacteria, leading to intestinal inflammation.

Our approach to Crohn's disease

UCSF provides comprehensive evaluations and advanced care for all types of IBD, including Crohn's disease. Our team is made up of many kinds of specialists – such as gastroenterologists, surgeons, radiologists, pathologists, immunologists, nutritionists and psychologists – who work collaboratively to devise an individualized treatment plan for each patient. Our overarching goal is to improve our patients' quality of life.

In addition to caring for patients, our doctors are active in research to find new therapies for IBD and, ultimately, a cure. Interested patients may have the option to receive investigational treatments by participating in clinical trials.

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Signs & symptoms

Common symptoms of Crohn's disease include the following:

  • Loose, watery or frequent bowel movements
  • Abdominal cramps and pain
  • Fever
  • Rectal bleeding
  • Loss of appetite and subsequent weight loss

During periods of active symptoms, you also may experience:

  • Fatigue
  • Joint pain
  • Skin problems
  • Fissures, or tears in the lining of the anus
  • Fistulas, a tunnel that connects the intestine to the bladder, vagina or skin
  • Oral or skin lesions


First your doctor will ask about your medical history and perform a physical evaluation. There is no single test that can provide a diagnosis of Crohn's disease, but rather a series of X-rays, laboratory tests, endoscopy and pathology tests that are used. These may include the following:

  • Blood tests. Blood tests may be done to check for anemia, which may indicate bleeding in the intestines. Blood tests also may uncover a high white blood cell count, which is a sign of inflammation somewhere in the body. C reactive protein, a marker of inflammation, also may be elevated.
  • Stool sample. By testing a stool sample, the doctor can tell if there is bleeding or infection in the intestines.
  • Small bowel radiograph. Your doctor may perform a small bowel follow through to look at the small intestine. For this test, you will drink barium, a chalky solution that coats the lining of the small intestine, before X-rays are taken. The barium and irregularity of the border between the barium and intestine shows up white on X-ray film, revealing inflammation or other abnormalities in the intestine.
  • Colonoscopy. The term "colonoscopy" means looking inside the colon. The colon, or large bowel, is the last portion of your digestive tract. Its main function is to absorb water and store unabsorbed food products prior to their elimination. Colonoscopies are performed by a gastroenterologist, a doctor specially trained in digestive disorders. Your doctor will be assisted by specially trained nurses and technicians.

The procedure is performed using a colonscope. This device is a long, flexible tube that is about as thick as your index finger and has a small video camera and light on the end. By adjusting the various controls on the colonscope, the gastroenterologist can carefully examine the inside lining of the colon from the anus to the cecum and can enter the end of your small bowel, or terminal ileum, as well. The colonoscope contains a channel that allows instruments to be passed in order to take tissue or stool samples, remove polyps and provide other therapy.

The high quality picture from the colonoscope is shown on a television monitor. Colonoscopy provides the best imaging of the colon at present. It is a more precise examination than X-ray studies. This procedure also allows other instruments to be passed through the colonoscope. These may be used, for example, to painlessly remove a suspicious-looking growth or to take a biopsy, where a small piece of tissue is obtained, for further analysis. In this way, colonoscopy help doctors assess whether surgery is necessary as well as what type of surgery may be needed.


Although there is no cure for Crohn's disease, there are a number of treatment options available.

Drug therapy

Drugs are used to suppress the inflammatory response associated with Crohn's disease, which in turn helps the intestines to heal and relieves symptoms. Once symptoms are under control, medications are used to decrease the frequency of flare-ups and prevent symptoms from recurring. There are several types of drugs available to treat Crohn's disease including aminosalicylates, corticosteroids, immune modifiers and biologic therapy.


When medications become ineffective or there is a complication, such as an intestinal obstruction or fistula, surgery may be necessary. Typically, surgery will remove the diseased part of the bowel. The two healthy ends of the bowel are then joined together. Although surgery can provide many symptom free years, it is not considered a cure as the disease usually recurs. As surgery is not curative, it aims to remove as little as possible of the diseased part of the bowel.


During this surgical procedure, the surgeon creates a small opening in the abdomen, called a stoma, to which he or she attaches the end of the small intestine, called the ileum. Waste will travel through the small intestine and exit the body through the stoma, which is about the size of a quarter and is usually located in the lower right part of the abdomen near the beltline. A pouch is worn over the opening to collect waste and the patient empties the pouch as needed.

Nutrition supplementation

Your doctor may recommend nutritional supplements. A small number of patients may need to be fed intravenously from time to time. This can help those who temporarily need extra nutrition, whose intestines need to rest or whose intestines cannot absorb enough nutrition from food.

UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.

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