Aortoduodenal fistula: role of endoscopy in diagnosis.

A patient with an aortic by-pass graft presented with intermittent gastrointestinal bleeding. A definitive diagnosis of an aortoenteric fistula involving the third part of the duodenum was made at endoscopy. Diagnosis of an aortoenteric fistula is often difficult with angiography and barium contrast studies, frequently being negative. Since the majority of these fistulas involve the distal duodenum, early endoscopy should be considered when an aortoenteric fistula is suspected.