Sporadic hemorrhagic colitis associated with Escherichia coli, type O157:H7: unusual presentation mimicking ischemic colitis.

Hemorrhagic colitis is a bacterial infection of the colon, associated with a verotoxigenic strain of Escherichia coli, commonly serotype O157:H7. This recently described disease is usually self-limiting. Because fecal cultures are negative for the usual pathogens and the clinicopathologic features closely mimic ischemic colitis, the patient is exposed to the risk of unnecessary surgery. One such situation is described and differentiation between hemorrhagic and ischemic colitis is discussed.