Risk factor of cholelithiasis is rapid weight loss after bariatric surgery and change in the gallbladder function which is secondary to surgery. Many observational studies support this fact, and a high incidence of 28% -71% after gastric bypass surgery (RYGB) was reported in them. According to another publication, the incidence of gallbladder diseases is 5-36% after jejunoileal bypass surgery and 2.8-36% after gastric bypass surgery.