Ischemic colitis is a transient reduction in blood flow to the colon.
Necrosis may occur but is usually limited to the mucosa and submucosa, only occasionally causing full-thickness necrosis necessitating surgery. Ischemic colitis occurs mainly in older people (> 60) and is thought to be caused by small-vessel atherosclerosis. It can also be a complication of abdominal aortic aneurysm repair.
Symptoms are milder and of slower onset than those of acute mesenteric ischemia and consist of left lower quadrant pain followed by rectal bleeding. Diagnosis is made by CT or colonoscopy; angiography or magnetic resonance angiography is not indicated. Treatment is supportive with IV fluids, bowel rest, and antibiotics. Surgery is rarely required, unless ischemic colitis is a complication of a vascular procedure or there is full-thickness necrosis. About 5% of patients have a recurrence. Occasionally, strictures develop at the site of the ischemia several weeks later, necessitating surgical resection.
Last full review/revision August 2012 by Parswa Ansari, MD