The Roux-en-Y Gastric Bypass, often called gastric bypass, is considered the ‘gold standard’ of
weight loss surgery.
There are two components to the procedure. First, a small stomach pouch 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 the small intestine will eventually
mix with the food.
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.
- 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 favourable changes in gut hormones that reduce appetite and enhance satiety
- Typical maintenance of > 50% excess weight loss