Roux-en-Y Gastric Bypass
The
gastric bypass works by several mechanisms. First, similar to most bariatric
procedures, the newly created stomach pouch is considerably smaller and
facilitates significantly smaller meals, which translates into less calories
consumed. Additionally, because there is less digestion of food by the smaller
stomach pouch, and there is a segment of small intestine that would normally
absorb calories as well as nutrients that no longer has food going through it,
there is probably to some degree less absorption of calories and nutrients.

Most importantly, the rerouting of the food stream produces changes in gut hormones that promote satiety, suppress hunger, and reverse one of the primary mechanisms by which obesity induces type 2 diabetes.
Benefits:
- Produces significant long-term weight loss
(60 to 80 percent excess weight loss)
- Restricts the amount of food that can be
consumed
- May lead to conditions that increase energy
expenditure
- Produces favorable changes in gut hormones that reduce appetite and enhance satiety
How it works:
- First, a small stomach pouch, approximately one ounce or 30
milliliters in volume, is created by dividing the top of the stomach from the
rest of the stomach.
- Next, the first portion of the small intestine is divided, and
the bottom end of the divided small intestine is brought up and connected to
the newly created small stomach pouch.
- The procedure is completed by connecting the top portion of the divided small intestine to the small intestine further down so that the stomach acids and digestive enzymes from the bypassed stomach and first portion of small intestine will eventually mix with the food.