Endoscopy is essential in the assessment and treatment of the bariatric patient, especially in the postoperative state. Since bariatric surgery is increasing exponentially, endoscopists should be familiar with the anatomy and how to manage possible complications. New less invasive therapeutic tools will have a major impact on the prognosis of these patients. Dreaded complications such as leaks, stenosis or weight regain can be successfully assessed and treated by endoscopy. Postoperative evaluation of symptoms requires the precise search of details that can change patient's management.