The prevalence of bariatric surgery procedures has increased dramatically in recent years and multiple specialties encounter bariatric patients. In this article, we outline the different options in bariatric surgery and summarized the recommendations for gastrointestinal assessment of candidates before and after bariatric surgery. The role of routine endoscopy was controversial in pre surgical evaluation but may alter the operation performed. Comprehensive pre-operative screening conducted by a multidisciplinary team including gastroenterologist was essential to prepare obese patients for successful outcome following surgery. The most commonly performed procedures were Roux-en-Y gastric bypass and adjustable gastric banding. We presented the early and late complications of bariatric surgery and recommendations for post-operative cares by gastroenterologist in this review article