In the Surgical Clinic of the University of Münster Billroth II resection with Roux-en-Y gastroenterostomy was introduced 1974--with a specific modification-- and has now been performed in every case where primary or additional resections of the stomach were indicated. The main advantage is seen in the tensionless gastroenteral anastomosis even in cases with high resection. In ulcer surgery, the method permits to remove safely the main gastrin-producing parts of the stomach, and to reduce the mass of acid-producing parietal cells. At the same time it is possible to avoid duodeno-gastric reflux which is held responsible for promoting carcinomas in the gastric remnant. The use of the Roux loop guarantees reflux-free resection and provides an effective prophylaxis of gastric stump carcinoma. After this type of operation bile reflux is never seen on endoscopy.