Since the Duodenal Switch process directly affects the metabolism, it causes more weight loss. It is an applicable method especially for people with BMI more than 50 Kg / m2. In this surgery, both food intake is restricted and the absorption of foods taken is reduced. It is an effective method in the treatment of diabetes, hypertension and high cholesterol diseases due to excess weight. Since it is an application that reduces fat absorption, it is an effective surgery for patients consuming fatty foods. Although it is among the surgical methods that provide the most weight loss in obesity surgery, it is not used very often due to the excess of postoperative complications. After this surgery, malodorous chronic diarrhea and vitamin and protein deficiencies due to decreased fat absorption are common. The stomach is tubed and the first part of the duodenum is cut. A 250 cm feeding path is created from the place where the small intestine connects to the large intestine and connects to the duodenum. The starting part is also connected to the distal and a common channel is created.