Gastric bypass is one of the most commonly performed types of bariatric surgery. Gastric bypass is done when diet and exercise haven't worked or when you have serious health problems because of your weight.

Gastric bypass, or Roux-en-Y (roo-en-wy) gastric bypass, is a type of weight-loss surgery that creates a small pouch from the stomach and connects the newly created pouch directly to the small intestine. After gastric bypass, swallowed food will go into this small pouch of stomach and then directly into the small intestine, bypassing most of your stomach and the first section of your small intestine.

This procedure is recommended for people:

- with a body mass index (BMI) of 40 or higher (extreme obesity).

- Your BMI is 35 to 39.9 (obesity),with serious weight-related health problems, such as type 2 diabetes, high blood pressure or severe sleep apnea.

-when diet and exercise haven't worked or when you have serious health problems because of your weight.