Surgery for Severe Obesity (IMAGE) University of Basel Caption Two types of surgery for severe obesity: In the case of gastric bypass, the stomach is bypassed by a part of the small intestine (left), while in the case of the peritoneum, the stomach volume is reduced (right). Credit USZ, Visceral Surgery Usage Restrictions Give adequate attribution to the original author License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.