There are three types of gastric bypass procedures: Roux-en-Y gastric bypass, mini-gastric bypass, and extensive gastric bypass, or biliopancreatic diversion. All three forms of weight loss surgery are conducted to curtail and treat morbid obesity and the health problems that accompany it. The processes involved in each type of gastric bypass procedure are slightly different, but all of them share a common goal: reduce the patient's appetite and decrease calorie intake and absorption.
In Roux-en-Y gastric bypass procedures, or RGB, a section of the stomach is either stapled together or cordoned off by an elastic band. The remaining portion of the stomach resembles a small pouch, and it is through this pouch that will food will now pass. The pouch is then affixed to the lower portion of the small intestine, allowing food to bypass the upper portion — the duodenum — entirely. The duodenum absorbs much of the body's fat intake, and by skirting this part of the intestinal tract, significantly less fat is taken in by the body. RGB is one of the most commonly performed surgical weight-loss procedures.
Mini-gastric bypass surgery entails attaching the stomach to a specially designed tube. Unlike RGB, it does not involve fashioning the stomach into a small pouch, but rather staples the stomach to the tube, which is implanted on the side of the stomach nearest the small intestine. With this surgery, food passes directly through the stomach and tube and into the lower part of the small intestine, avoiding the duodenum. Mini-gastric bypass is a relatively short operation — approximately 30 minutes — and the recovery time is much quicker than other gastric bypass procedures.
An extensive gastric bypass, also known as a biliopancreatic diversion, is the most difficult weight loss procedure of the three. Instead of sectioning off the stomach into a pouch and leaving the rest of the organ intact, this surgery involves the total removal of the remaining stomach after the pouch is crafted. As in RGB, the pouch is linked up with the lowest section of the small intestine, skirting the duodenum. The large intestine that would otherwise be attached to the stomach is closed up and left separated. This complex procedure is not widely performed as significant nutritional absorption problems have arisen in many patients.
Drastic weight loss and healthy weight maintenance are common results of gastric bypass procedures. But, as with any major operation, there are risks. Doctors advising individuals who are considering gastric bypass often stress that this is a serious medical procedure with its own set of complications and rewards.