Insidious gastrointestinal bleeding from a secondary aortic fistula poses a significant diagnostic challenge. Failure to recognize it early on can lead to devastating outcomes. We describe a case of insidious gastrointestinal bleeding from a secondary aortic fistula in an elderly woman who presented with recurrent admissions for melanotic stools and eventually developed septic shock. Esophagogastroduodenoscopy did not reveal any obvious source of bleeding. The patient eventually had push endoscopy that revealed infected graft and a secondary aortoduodenal fistula. One should proceed with push enteroscopy in occult bleeding if the patient has a history of abdominal aortic aneurysm repair.