An aortoenteric fistula is a connection between the aorta and the intestines, stomach, or esophageus.^[1] There can be significant blood loss into the intestines resulting in bloody stool and death.^[1] It is usually secondary to an abdominal aortic aneurysm repair. The third or fourth portion of the duodenum is the most common site for aortoenteric fistulas, followed by the jejunum and ileum.^{[citation needed]}

Diagnosis is typically via a CT angiography, esophagogastroduodenoscopy, or arteriography.^[1] It is part of the differential diagnosis of gastrointestinal bleeding.^[2]