Crohn's disease is a chronic condition in which there is chronic inflammation in the gastrointestinal (GI) tract or "bowel." It is one type of inflammatory bowel disease (IBD). Another type of IBD is ulcerative colitis. While Crohn's disease can affect any part of the digestive system from the mouth to the anus, it occurs more commonly in the ileum (part of the small intestine) and colon (large intestine).
Most cases of Crohn's disease are diagnosed before the age of 30, but it can affect people of any age group. Crohn's disease isn't usually fatal, but it can be a lifelong inconvenience. There is no definitive cure.