A duodenal switch (also referred to as DS or the “switch”) is a more complicated operation primarily offered to very heavy patients at the more extreme end of what is seen. It is the most effective procedure, but can have a higher complication rate. It involves bypassing the majority of the small intestine, so the risk of malabsorption is an important piece. The vitamin issues that doctors are concerned about are more of a concern long-term, but the weight loss results are profound.
The intention of this procedure is to help people who have the most weight to lose and who are typically struggling with severe diabetes. It is not just to lose the weight, but to correct the metabolic problems that are causing them to hold onto weight even more-so than a sleeve gastrectomy and a gastric bypass can.
If a patient has a sleeve and needs to lose more weight, it can be converted to a switch as a second stage to the operation, and with that achieve very good results that are more effective than doing a more complicated operation in the first pass.