Crohn's disease is a form of inflammatory bowel disease that causes inflammation and ulcers that may affect the deepest layers of the lining of the digestive tract. It can also cause abnormal openings or connections (fistulas) in the diseased intestine.

Crohn's disease is different from ulcerative colitis in that it can affect any part of the digestive tract. Symptoms of Crohn's disease include episodes of diarrhea, abdominal pain, fever, nausea, loss of appetite, and weight loss. People with Crohn's disease may sometimes need to be hospitalized for treatment of their symptoms.

Treatment depends on the severity of the attacks and the person's age. It may include medications and, sometimes, surgery for serious cases.