There are many types of colitis, which means an inflammation of the colon. One type is called ischemic colitis. In this situation, the blood supply to a segment of the colon is reduced or even blocked entirely by a cholesterol plaque or a blood clot. The bowel wall then becomes damaged as nutrition and oxygen can not be delivered to the colon. The bowel becomes inflamed and whitish. Often there is acute abdominal pain with some diarrhea progressing to blood in the stool. Sometimes these heal on their own. At others, surgery may be needed. In this instance, the diagnosis was proven by biopsy.