The procedure reduces the stomach to a small pouch and diverts food around part of the small intestine. Less food is absorbed and the individual feels full sooner, leading to weight loss.

胃旁路手术是常见的减肥术，该手术方式为减小胃囊，改变食物进入小肠的路径，使受术者术后吃饭时很快产生饱腹感、减少食物的吸收。