Ischemic Colitis

ByParswa Ansari, MD, Hofstra Northwell-Lenox Hill Hospital, New York
Reviewed/Revised Apr 2023
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Ischemic colitis is a transient reduction in blood flow to the colon. Symptoms are left lower quadrant pain and rectal bleeding. Diagnosis is by CT or colonoscopy. Treatment is supportive with IV fluids, bowel rest, and antibiotics.

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 and Signs of Ischemic Colitis

Symptoms of ischemic colitis are milder and of slower onset than those of acute mesenteric ischemia and consist of left lower quadrant pain followed by rectal bleeding. The pathophysiology and treatment of the two conditions are quite different.

Diagnosis of Ischemic Colitis

  • CT or colonoscopy

Diagnosis of ischemic colitis is made by CT or colonoscopy.

Ischemic Colitis (CT Scan)
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In this CT scan, the descending colon (top arrow) is thick-walled from the splenic flexure to the proximal sigmoid colon. Note the distal sigmoid colon (bottom arrow) with diverticulosis but without inflammatory or ischemic changes.
Image provided by Parswa Ansari, MD.
Ischemic Colitis (Colonoscopy)
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In this colonoscopy image, the mucosa is diffusely erythematous and ulcerated, consistent with moderate-to-severe ischemic colitis.
Image provided by David M. Martin, MD.

Angiography or magnetic resonance angiography is not indicated.

Treatment of Ischemic Colitis

  • IV fluids, bowel rest, and antibiotics

  • Rarely surgery

Treatment of ischemic colitis is supportive with IV fluids, bowel rest, and antibiotics.

The underlying cause of the low-flow state (eg, control of cardiac arrhythmia) is treated if relevant.

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.

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