Obesity is a growing problem in developed countries, and surgery is the most effective treatment in terms of weight loss and improving medical comorbidity in a high proportion of obese patients. Despite the advances in surgical techniques, some patients still develop acute and late postoperative complications, and an endoscopic evaluation is often required for diagnosis. Moreover, the high morbidity related to surgical reintervention, the important enhancement of endoscopic procedures and technological innovations introduced in endoscopic equipment have made the endoscopic approach a minimally-invasive alternative to surgery, and, in many cases, a suitable first-line treatment of bariatric surgery complications. There is now evidence in the literature supporting endoscopic management for some of these complications, such as gastrointestinal bleeding, stomal and marginal ulcers, stomal stenosis, leaks and fistulas or pancreatobiliary disorders. However, endoscopic treatment in this setting is not standardized, and there is no consensus on its optimal timing. In this article, we aim to analyze the secondary complications of the most expanded techniques of bariatric surgery with special emphasis on those where more solid evidence exists in favor of the endoscopic treatment. Based on a thorough review of the literature, we evaluated the performance and safety of different endoscopic options for every type of complication, highlighting the most recent innovations and including comparative data with surgical alternatives whenever feasible.

• Bariatric surgery
• Bariatric complications
• Endoscopic treatment
• Leaks
• Stenosis
• Sleeve gastrectomy
• Gastric Roux-en-Y bypass