OBJECTIVES: Roux-en-Y gastric bypass (RYGB) is a common intervention for morbid obesity. Upper gastrointestinal (UGI) symptoms are frequent and difficult to interpret following RYGB. The aim of our study was to examine the role of endoscopy in evaluating UGI symptoms after RYGB and to assess the safety and efficacy of endoscopic therapy.METHODS: Between 1998 and 2005, a total of 1,079 patients underwent RYGB for clinically severe obesity and were followed prospectively. Patients with UGI symptoms after RYGB who were referred for endoscopy were studied. RESULTS: Of 1,079 patients, 76 (7%) who underwent RYGB were referred for endoscopy to evaluate UGI symptoms. Endoscopic findings included normal surgical anatomy (n=24, 31.6%), anastomotic stricture (n=40, 52.6%), marginal ulcer (n=12, 15.8%), unraveled nonabsorbable sutures causing functional obstruction (n=3, 4%) and gastrogastric fistula (n=2, 2.6%). Patients with abnormal findings on endoscopy presented with UGI symptoms at a mean of 110.7 days from their RYGB, which was significantly shorter than the time of 347.5 days for patients with normal endoscopy (PCONCLUSIONS: Patients presenting with UGI symptoms less than 3 months after surgery are more likely to have an abnormal finding on endoscopy. Endoscopic balloon dilation is safe and effective in managing anastomotic strictures. Endoscopic scissors are safe and effective in removing unraveled, nonabsorbable sutures contributing to obstruction.