Primary aortoenteric fistula: should enhanced computed tomography be considered in the diagnostic work-up?

We present the case of a 66-yr-old woman who was admitted to a surgical intensive care unit with life-threatening rectal bleeding. Despite the use of angiography and repeated computed tomography scans, the diagnosis of a primary aortoduodenal fistula secondary to an abdominal aortic aneurysm was not made, leading to a delay in diagnosis until the time of surgery. The reliability of radiological investigations and the importance of being alert to the possibility of this extremely rare condition are discussed.