Roux-en-Y Gastric Bypass
In a gastric bypass surgery, a patient has his or her stomach stapled using surgical staples that create a small pouch at the top of the stomach. Surgeons then attach a part of the small intestine to the small, newly created pouch. When the person eats, food will go into the small pouch, bypassing most of the stomach, and then continue through the attached part of small intestine and through the rest of the digestive tract.
(Click the image to the right for a larger view of the diagram).
Having your stomach stapled helps you to lose weight in three ways:
Reducing the amount of food you can eat – Having your stomach stapled creates a stomach pouch that can only hold about 2 to 4 tablespoons at a time. Also, the connection between this pouch and the small intestine has a small opening, only 1/3 to ½ inch wide. These two factors drastically reduce the amount of food that you can eat at one time.
Decreased ability of the body to absorb nutrients and calories – Normally, the body absorbs some nutrients and calories when food is in the stomach and small intestine. With these two areas bypassed, the body has less ability to absorb digestive material. The fewer calories the body absorbs, the greater the weight loss.
Appetite reduction – It is not well understood why, but the surgical bypass interferes with the appetite regulation process of the body. Although people eat less after surgery, they also experience reduced hunger.