This surgery is performed under general anesthesia and takes approximately four hours. In the first step of the procedure, the surgeon decreases the size of the stomach, which is normally the size of a football, to the size of an egg. To do this, the surgeon staples the stomach together, leaving only a small pouch at the top. He then cuts the small intestine at the jejunum and attaches it to the newly formed stomach pouch. This Roux limb ensures that food will bypass the remaining part of the stomach and the first part of the small intestine.
The section of the small intestine still attached to the lower part of the stomach -- the duodenum -- is then reattached to the middle section of the small intestine, creating a Y-formation just below the stomach. This reattachment allows the stomach to stay healthy enough to continue secretion of digestive juices, which are carried to the midsection of the small intestine to aid in digestion.
These steps make people who have had gastric bypass surgeries feel full sooner, so they don't consume as many calories. They also absorb fewer calories through the small intestine. Patients then burn more calories than they absorb and lose weight as a result.
When surgeons first started performing gastric bypass surgeries, they began by making a large incision in the abdomen. Now, many surgeons perform gastric bypass surgeries through a very small incision. The surgeon inserts a narrow tool called a laparoscope into the incision. The surgeon can guide a tiny camera through this tube to see what is going on inside the abdomen. Doctors and patients often prefer this laparoscopic technique due to its faster recovery rate and decreased risk factors.
During the procedure, patients also have a tube inserted into their nose and passed down to the new, smaller stomach pouch. The tube connects to a suction device that keeps the pouch empty, helping it heal correctly. This surgery is usually completed in about four hours, and most patients stay in the hospital for two to six days to be monitored for any complications.