What Is Ulcerative Colitis? What Causes Ulcerative Colitis?

Ulcerative colitis is a fairly common chronic (long-term) disease that causes inflammation of the colon (the large intestine). It is a form of inflammatory bowel disease that has some similarity to Crohn's disease, a related disorder. The colon - or large intestine - removes nutrients form undigested food and gets rid of waste products through the rectum and anus when we pass feces (stools).