Crohn's Disease

Am Fam Physician. 2011;84(12):1379-1380

See related article on Crohn's disease.

What is Crohn's disease?

It is a disease that causes inflammation in the digestive tract (gut). Crohn's disease usually happens in young adults.

What are the symptoms?

Common symptoms include diarrhea, stomach pain, weight loss, fever, and bleeding from the rectum; however, most patients find that their symptoms change over time. In patients with severe disease, the gut may be blocked, which can cause pain and other symptoms. Crohn's disease can also cause problems in other parts of the body, especially the joints or eyes. Smoking can make the symptoms worse. Patients with Crohn's disease also have a higher risk of getting colon cancer and need to be monitored regularly.

How is it diagnosed?

Colonoscopy is the best test to diagnose Crohn's disease. Before getting a colonoscopy, you will need to take a laxative to clear stool out of your colon. Your doctor will then use a flexible scope with a small camera and light to look inside your gut for areas of inflammation. Your doctor may take a sample of gut tissue (called a biopsy) to test for Crohn's disease.

Several other tests are sometimes used to help diagnose Crohn's disease or to look for complications. Your doctor may do blood tests to figure out your vitamin B₁₂, folate, and protein levels. Blood tests can also help find out if you have anemia.

Computed tomography (CT), magnetic resonance imaging (MRI), and small bowel x-rays are tests that look at your stomach and digestive tract. With these tests, you may be given a special dye that you drink or have injected to help your doctor see a certain area of your body better.

Ultrasonography uses sound waves to produce images of your body. It does not require drinking special dyes.

How is it treated?

Treatment depends on the type of symptoms you have. Crohn's disease cannot be cured, but medicine can help with symptoms. Several different types of medicine are used, including:

Aminosalicylates. These medicines can be given by mouth or into the rectum to help control inflammation. Examples: sulfasalazine (one brand: Azulfidine), mesalamine

Corticosteroids (also called steroids). These medicines decrease the activity of the immune system. They are used for a short time and may be combined with aminosalicylates. Examples: prednisone, budesonide (one brand: Entocort EC)

Antibiotics. The most common antibiotics used to treat Crohn's disease are metronidazole (one brand: Flagyl) and ciprofloxacin (one brand: Cipro)

Immunomodulators. These medicines decrease the activity of the immune system, and are usually used if symptoms are not well controlled by other treatments. Examples: azathioprine (one brand: Imuran), 6-mercaptopurine, methotrexate

Biologic therapies. These medicines reduce inflammation. You should have a tuberculosis test before taking these medicines. Examples: adalimumab (one brand: Humira), certolizumab pegol (one brand: Cimzia), infliximab (one brand: Remicade)