Secondary arterioenteric fistula involving the sigmoid colon.

An arterioenteric fistula is a life-threatening condition. Whereas most arterioenteric fistulae involve the duodenum, they can occur at any point along the gastrointestinal tract, and those to the lower tract may present with less classic symptoms than arterioduodenal fistulae. It is likely that more patients with arterioenteric fistulae will present to the emergency department (ED) in the future because of an increasing number of elective aortic aneurysm repairs in an aging population. We present a patient with a secondary fistula involving the sigmoid colon who presented to the ED with abdominal pain and a tender abdominal mass.