 [ Symptoms ] what is crohn is disease [ Disease ] crohn is disease is a chronic inflammatory disease of the intestines it primarily causes ulcerations breaks in the lining of the small and large intestines but can affect the digestive system anywhere from the mouth to the anus it is named after the physician who described the disease in 1932 it also is called granulomatous enteritis or colitis regional enteritis ileitis or terminal ileitis crohn is disease is related closely to another chronic inflammatory condition that involves only the colon called ulcerative colitis together crohn is disease and ulcerative colitis are frequently referred to as inflammatory bowel disease ibd ulcerative colitis and crohn is disease have no medical cure once the diseases begin they tend to fluctuate between periods of inactivity remission and activity relapse they affect approximately 500 000 to 2 million people in the united states men and women are equally affected ibd most commonly begins during adolescence and early adulthood but it also can begin during childhood and later in life crohn is disease tends to be more common in relatives of patients with crohn is disease it also is more common among relatives of patients with ulcerative colitis