what causes colitus
1 Colitis is inflammation of the inner lining of the colon. 2  It may cause abdominal pain and diarrhea with or without blood. 3  Fever may be present. 4  There are numerous causes of colitis including infection, inflammatory bowel disease, ischemic, and microscopic colitis. Fever may be present. 2  There are numerous causes of colitis including infection, inflammatory bowel disease, ischemic, and microscopic colitis. 3  Blood in the stool is never normal and should not be ignored. 4  Depending upon the history and physical examination, further testing may be required to find the cause of colitis.