This technique, which is frequently used in Europe, especially in Italy, has been used since 1976. The basic principle in this technique is to disrupt the absorption of oil and starch. The size of the new stomach is larger than in other operations. Only 2/3 of the last part of the stomach is removed and the remaining part of the stomach and small intestines at a distance of 250 cm from the junction with the large intestine (ileo-cecal region) is cut and sutured.
The bypassed intestine section is sutured 50 cm away from the ileocecal area. Since absorption is more impaired than gastric-bypass, close patient follow-up is essential with the use of supplements and formula in order to avoid deficiency of vitamins, minerals, iron, calcium and especially proteins.
As an alternative to classical biliopancreatic diversion surgery, the duodenal switch technique has been introduced in the USA. In this technique, instead of the upper part of the stomach, the tube is cut longitudinally as in the sleeve gastrectomy and the first part of the duodenum is protected from bypass. The success rates in this operation, where dumping syndrome and iron absorption are expected to be less impaired, are similar to those in BPD.