Diverticular bleeding in the third part of the duodenum as a cause of overt obscure gastrointestinal bleeding

A 65-year-old man with a history of chronic renal failure and ischemic heart disease who was receiving aspirin therapy was admitted for recurrent melena. Initial evaluation revealed severe anemia. Other than a diverticulum in the third part of the duodenum, the findings of upper and lower gastrointestinal endoscopies and computed tomography were unremarkable. Capsule endoscopy detected altered blood in the ileum; however, balloon-assisted enteroscopy found no definitive source of bleeding. Three years later, he presented with recurrent melena and hemorrhagic shock. Upper gastrointestinal endoscopy identified Dieulafoy's lesion within the duodenal diverticulum. Hemostasis was achieved using hemoclips. No recurrence of bleeding was observed during 4 years of follow-up. The findings from this case highlight the diagnostic and therapeutic challenges of managing obscure gastrointestinal bleeding due to Dieulafoy's lesion in a diverticulum in the third part of the duodenum. Duodenal diverticular bleeding should be included in the differential diagnoses for patients with obscure gastrointestinal bleeding.