The patient has an aortoenteric fistula, a potentially life-threatening condition. The patient has a sentinel bleed-a self-limited episode of bleeding sometimes seen prior to a massive bleeding episode. Observation is contraindicated because the lesion is very likely to re-bleed. Neither a tagged erythrocyte scan nor an aortic ultrasound would offer additional information. Endoscopic closure of the defect is unlikely to prevent further bleeding. Surgical therapy should be undertaken immediately to repair the graft and achieve primary closure of the duodenal defect.