Duodenal Switch - Part I

The Duodenal Switch surgery for weight loss was classified by the National Institutes of Health as “extensive gastric bypass with duodenal switch”. Researchers from the University of Chicago found that this surgical procedure for weight loss produces substantially better weight-loss outcomes for super obese patients than the standard operation, the Roux-en-Y gastric bypass.

The 'Duodenal Switch', which refers to the re-routing of a section of the small intestine, is just a portion of the actual surgery, however. This gastric bypass surgical procedure is officially known as a biliopancreatic diversion with duodenal switch, and is often referred to by its initials BPD/DS. The BPD/DS is the only bariatric surgery in which a major portion of the stomach is permanently removed. This is the first reason that this operation is often seen as a “bigger” surgery than some of the other types of gastric bypass surgery. The second reason is that a large portion of the small intestine is bypassed.

A considerable section of the small intestine is re-routed, creating three passageways: two separate pathways and one common pathway. The shorter of the two separate passageways carries food from the stomach to the large intestine. The other pathway, which is much longer, is called the bilio-pancreatic loop, because it carries bile from the liver to the common path. The common path is a portion of small intestine which is usually 75-150 centimeters long. In this channel, the contents of the digestive path mix with the bile from the bilio-pancreatic loop before emptying into the large intestine. The reason these passageways are created and diverted from their normal courses in the body is so that the amount of time the body has to capture calories from food in the small intestine is severely reduced and so that the absorption of fat selectively limited. The duodenum lies just below the stomach and is the first and shortest portion of the small intestine. It is here that most of the chemical digestion takes place in the body.