Aortoenteric Fistula: A Differential Diagnosis of Anemia.

Aortoenteric fistulas (AEFs) are a rare and deadly cause of gastrointestinal bleeding that can be easily overlooked, leading to massive bleeding. Secondary AEFs are more common than primary AEFs. An example of a secondary cause of anemia is postoperative hemorrhage due to a surgically placed aortic graft or after endovascular aneurysm repair.