Duodenal switch surgery is a laparoscopic weight loss procedure that combines two techniques in one, with the goal of making the stomach smaller and rerouting the intestines. Together, these two components prove to be an effective way to lose weight and improve health issues caused by being overweight. The two techniques used to complete duodenal switch surgery include: Restrictive Component: This part of the procedure involves creating a gastric sleeve by reducing the size of the stomach to limit the amount of food and calories that can be ingested. We will divide the stomach vertically and remove two-thirds of it. The remaining stomach is shaped like a banana and is reduced to 8-10 ounces. Malabsorptive Component: This part of the procedure rearranges the duodenum, or the first part of the small intestine, which separates the flow of food from the Trusted Source Duodenal Switch (PBD-DS) Columbia Surgery. Go to Source flow of digestive juices . The rearrangement causes the food to empty directly into the end of the small intestines, bypassing most of the digestive tract. This results in malabsorption, in which fewer calories and nutrients are absorbed by the body, helping to aid in weight loss.