This technique, which is frequently applied in Europe, especially in Italy, has been used since 1976. The basic principle in this technique is to disrupt the absorption of fat and starch. The size of the new stomach is larger than in other operations. Only the 2/3 last part of the stomach is removed and the residue stomach is sutured with a part 250 cm further from the junction point of small intestines with the colon (ileo-cecal area). The by-passed intestinal region is sutured 50 cm further from the ileocecal area. Because absorption is more impaired than gastric-bypass, close patient follow-up is necessary with additional nutritional supplements and use of food to prevent the deficiency of vitamins, minerals, iron, calcium and especially proteins.
As an alternative to classical biliopancreatic diversion surgery, duodenal switch technique has been introduced in America. In this technique, the stomach is incised vertically as in sleeve gastrectomy instead of removing the upper part and the first part of the duodenum is protected from being bypassed. Dumping syndrome and iron absorption are expected to be less degraded in this operation, and success rates are similar to BPD.