One of the most acceptable procedures in bariatric surgery is laparoscopic gastric bypass. Laparoscopic Roux-en-Y gastric bypass (RYGB) is a common technique used in bariatric surgery. Recently, one anastomosis gastric bypass (OAGB) has been suggested as a simple, fast, and effective technique for obesity treatment. This study aims to compare the frequency of histologically proven bile reflux in OAGB and RYGB among patients with morbid obesity.