Ulcerative Colitis is a chronic inflammatory condition that causes ulcers and inflammation in the lining of the large intestine [colon and rectum]. It is a type of inflammatory bowel disease. It is an autoimmune disease where the immune system attacks the gut microbes in the intestines, causing it to be inflamed. Apart from the gastrointestinal system, research suggests a connection between ulcerative colitis and various other health conditions.