The roux-en-y gastric bypass is a combined restrictive and malabsorptive operation. It is designed to restrict portion size by the creation of a small pouch out of the upper part of the stomach. The small instestine is surgically divided in a certain area and the lower portion is then brought up and connected to the newly-created, small stomach pouch. The upper portion (still connected to the larger section of the stomach) is then reattached to the small intestine, albeit further down from where it was initially divided. This forms somewhat of a Y-shape.
Food will bypass the larger section of the stomach and will pass directly into the small intestine. This reduces the amount of calories and nutrients the body absorbs thus increasing weight loss. This operation is particularly effective for curing and improving type 2 diabetes.
A sleeve gastrectomy operation is a restrictive procedure. The surgeon creates a long narrow tube out of the stomach. The rest of the stomach is removed. There is no bypass of the intestine. The operation is designed to restrict portion size and slow down the passage of food through the stomach.
Laparoscopic Adjustable Gastric Banding Procedure (Lap Band)
During a Lap Band procedure, a hollow band made of silicone is placed around the stomach near its upper end, creating a small pouch and a narrow passage into the rest of the stomach. The band is connected to a port that is placed on the abdominal wall under the skin. This port is accessed by a needle in the clinic and fluid is injected to tighten the band. Fluid can be withdrawn if the band is too tight.