Push-enteroscopy for diagnosis of patients with gastrointestinal bleeding of obscure origin. Push-enteroscopy using a disinfected colonoscope was performed on 39 patients with gastrointestinal bleeding of obscure origin. Our results show that: (1) A high percentage of patients (38%) have pathological lesions responsible for bleeding located in the distal duodenum and proximal jejunum, which are readily detected by push-enteroscopy. (2) Duodeno-jejunal arteriovenous malformations (AVMs) are the most common cause for bleeding, and these lesions can be conveniently cauterized through the endoscope. (3) An efficient sequence of steps for diagnosis of patients with this problem includes push-enteroscopy when the initial EGD and colonoscopy are normal followed by small bowel radiography. Mesenteric angiography and intraoperative enteroscopy can be reserved for patients with severe bleeding when push-enteroscopy and small bowel radiography are negative. We conclude that push-enteroscopy has an important role to play in the early assessment of patients with gastrointestinal bleeding of obscure origin. 