What Is Gastric Bypass Surgery?
Roux-en-Y gastric bypass surgery is one of the most common weight loss surgeries, accounting for about 47% of all weight loss surgeries. The procedure has two parts:
Part One: Making a Small Pouch in the Stomach
The surgeon divides the stomach into a large portion and a much smaller one. Then, in a process sometimes called "stomach stapling,†the small part of the stomach is sewn or stapled together to make a pouch, which can hold only a cup or so of food.
With such a small stomach, people feel full quickly and eat less. This strategy is also called "restrictive," because the new stomach size restricts how much food it can hold.
https://www.webmd.com/diet/obesity/what-gastric-bypass-surgery#1
