Laparoscopic Gastric Bypass is the most commonly performed bariatric procedure. It is a combination procedure (both restrictive and malabsorptive). The stomach is reduced in size, and parts of the small intestine, where most of the calories are absorbed, are re-routed. A small stomach pouch is created by stapling off the upper part of the stomach from the lower part. This significantly limits the amount of food a person can eat in one meal.
The second part of the small intestine is then connected to the pouch, and further down is connected to the first part of the small intestine. This allows food to bypass the majority of the stomach and the first part of the small intestine. This often results in vital changes in the body such as the resolution of diabetes in the vast majority of patients. It also allows patients to feel satisfied from only a small amount of food so they eat less.