Abstract: The clinical data of one patient with acute massive lower gastrointestinal bleeding caused by colonic Dieulafoy's disease was retrospectively analyzed, and the key points of clinical diagnosis and treatment were summarized in combination with the relevant diagnostic and therapeutic characteristics of the disease.Dieulafoy's disease is of unknown etiology and is essentially a submucosal arterial malformation, with a higher incidence in patients with underlying diseases or those taking anticoagulant, antipyretic and analgesic drugs for a long time.It most commonly occurs in the stomach and can involve any other part of the gastrointestinal tract.Acute massive lower gastrointestinal bleeding caused by colonic involvement is clinically rare.Endoscopy is the main method for locating the bleeding source of the disease, but the overall diagnostic difficulty is high, especially for colorectal lesions, and misdiagnosis or delayed treatment can lead to death.

Key words: dieulafoy's disease; colon; lower gastrointestinal bleeding; laparotomy