The bleeding of Dieulafoy lesion predominantly involves the proximal stomach and leads to severe gastrointestinal bleeding. However, these lesions have also been reported in the whole gastrointestinal tract. Bleeding of Dieulafoy lesions at the anastomosis was seldomly reported and was very easy to be ignored clinically.We describe a 72-year-old woman with a past history of surgery for rectal carcinoma hospitalized with chief complaint of massive rectal bleeding. No gross bleeding lesion was found during the first emergency colonoscopy. Despite multiple blood transfusions, her hemoglobin rapidly dropped to 5.8 g/dL.She was diagnosed with Dieulafoy lesion at the colorectal anastomosis during the second emergency colonoscopy.Primary hemostasis was achieved by endoscopic hemostatic clipping. However, she experienced another large volume hematochezia 3 days later, and then received another endoscopic hemostatic clipping. She was improved and discharged. However, this patient underwent hematochezia again 1 month later. Bleeding was arrested successfully after the over-the-scope clip (OTSC) was placed during the fourth emergency colonoscopy.This patient underwent 4 endoscopic examinations and treatments during 2 hospitalizations. The lesion was overlooked during the first emergency colonoscopy. The second and third endoscopes revealed Dieulafoy lesion at the colorectal anastomosis and performed endoscopic hemostatic clippings, but delayed rebleeding occurred. The bleeding was stopped after the fourth emergency colonoscopy using OTSC. There was no further rebleeding during hospitalization and after 2-year of follow-up.As far as we know, there is no reported case of lower gastrointestinal bleeding caused by Dieulafoy lesion at the colorectal anastomosis, OTSC is a safe and effective rescue treatment for Dieulafoy lesions.Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.