BACKGROUND. Roux-en-Y gastric bypass (RYGBP) is the most commonly performed bariatric operation in the US . Depending on the technique used (hand-sewn, linear stapler, circular stapler), the incidence of gastrojejunal anastomotic stricture varies between 5 and 20%. Endoscopic dilation is the treatment of choice for anastomotic stricture, however the recommendations regarding the timing and optimal method vary among surgeons and gastroenterologists. We have reviewed our experience with endoscopic dilation of anastomotic strictures following RYGBP. METHODS. Between October 2003 and October 2005, 182 patents (pts) underwent RYGBP for morbid obesity. The procedures were done laparoscopically in 158 (86%) cases. Gastrojejunostomy was made with a 21mm EEA stapler in 112 and in a hand-sewn fashion (2 layers over 34 FR tube) in 70 pts. Endoscopic evaluation was performed using GIF 160 Olympus endoscope (external diameter of 8.6 mm). The stricture was diagnosed if anastomosis could not be intubated with the scope. All dilations were performed with controlled radial expansion (CRE) balloon dilators of increasing size (10-12-13.5 mm, one minute each). Recurrent strictures were dilated to 15 mm in a similar fashion. RESULTS. A total of 25 patients (13.7%) developed anastomotic strictures and underwent dilation at the mean time of 47 days after surgery (range 21 to 150 days). The presenting symptoms were postprandial nausea and vomiting for solids; in addition, 3 patients experienced severe retrosternal pain after eating. All pts tolerated dilation under IV sedation. No complications occurred. Most pts (n=21) required only one dilation; three had to have a repeat dilation, and one required three dilations. No surgical revisions were necessary. The rate of stricture was slightly lower in the hand-sewn group: 11.4% vs. 15% (NS); there was a clear trend towards decrease in the stricture rate with experience in the hand-sewn group: out of first 35 anastomoses performed in this fashion 6 strictured (17%), while only 2 (5.7%) strictured in the second group of 35 pts. CONCLUSION. Anastomotic stricture after RYGBP (defined as inability to intubate the anastomosis with a 8.6 mm scope) occurred at a rate 13.7% in our series. Presenting symptoms are intolerance of solid food and postprandial vomiting. Endoscopic dilation with CRE balloon dilators performed as early as 21 days after surgery is safe and effective. Although samples are small, there is a strong trend towards decreased stricture rate if anastomosis is performed in a hand-sewn fashion, especially after the learning curve is passed.