Stomach stapling and other, similar types of weight loss surgery have become so common that they are now given their own classification: bariatric surgery.

Bariatric surgery is a name given to any type of surgery that involves a reduction in stomach size and/or a bypass of the normal sequence of digestion and absorption. The various types of bariatric surgery include: a) the banded gastroplasties - vertical banded gastroplasty (VBG), silastic ring gastroplasty (SRG) and adjustable ring gastroplasty (ARG); b) Roux-en-y gastric bypass and divided gastric bypass (the "gold standard" of bariatric surgery); c) biliopancreatic diversion.

All of these types of bariatric surgery begin by partitioning the stomach, either with staples or bands. Both of the types of bariatric surgery in (b) above begin with surgical stapling of one wall of the stomach to the opposite wall, resulting in two separate pouches. The larger pouch is essentially cut off from the digestive tract and does not take in any food. In all of these types of bariatric surgery, food enters the smaller pouch (about two ounces) and a very small meal quickly makes the stomach feel full. From this small pouch, food is re-routed past a long length of small intestine, thereby limiting the amount of food that is actually absorbed.

The banded gastroplasties are types of bariatric surgery that use a fancy rubber "band" wrapped around the stomach to similarly segment the stomach into small and large pouches. VBG staples off a small portion of stomach which is then banded; and ARG uses a band with a small tube that is implanted under the skin and used to fill the band with a variable amount of water to achieve the optimal size pouch. Digestion and absorption proceeds normally from there in this type of bariatric surgery.

Biliopancreatic diversion is a more drastic type of bariatric surgery that ties the stomach directly to the large intestine, bypassing the entire small intestine and resulting in very limited absorption of nutrients.

It is important to recognize that bariatric surgery will require severe modifications to diet and lifestyle. After bariatric surgery, it is important to eat small meals and to chew food thoroughly. Only after careful consideration of the risks and demands of bariatric surgery should bariatric surgery be chosen.