Abstract
Duodenal diverticular bleeding is a rare cause of upper gastrointestinal bleeding. We herein report a case of life-threatening duodenal diverticular bleeding with hypovolemic shock. Identifying the source of the hemorrhaging was difficult, and repeated endoscopic examinations - one colonoscopy and three esophagogastroduodenoscopy sessions - were required before the source was finally detected inside the diverticulum located in the third part of the duodenum. Hemostasis was successfully achieved using the hemoclips. Our case highlights the need to consider duodenal diverticulum bleeding in cases of suspected upper gastrointestinal bleeding without a clear source of bleeding.