Small bowel enteroscopy and intraoperative enteroscopy for obscure gastrointestinal bleeding. Intraoperative endoscopy (IOE) is accepted as the ultimate diagnostic procedure for completely evaluating the small bowel in patients with obscure gastrointestinal (GI) bleeding. Small bowel enteroscopy (SBE) has been reported useful in the nonsurgical evaluation of the small intestine in these patients, but findings may be limited because of incomplete small bowel intubation and a lack of tip deflection. Twenty-three patients underwent 25 SBE exams and subsequently had 25 IOE exams during surgical exploration for continued bleeding. Patients' bleeding histories averaged 2 yr, with an average transfusion requirement of 27 units. Findings on IOE were the same as with SBE in 17/22 (77%) of examinations. We conclude that SBE and IOE are comparable in depth of insertion and ability to detect small vascular ectasias. Both procedures missed pathology due to limited visibility and the evanescent nature of ectasias. Long-term success in abolishing bleeding with these combined techniques can be expected in 55% of these patients. SBE should precede surgery, since the finding of diffuse ectasias precludes any benefit from operative intervention. 