Commonly known simply as gastric bypass, this surgery involves creating a small pouch at the top of the stomach and attaching it to a lower segment of the small intestine, excluding a portion of the stomach and a portion of the small intestine. Patients lose weight because they eat less, but also because less of the food is absorbed. Roux-en-Y Gastric Bypass Surgery is considered the "gold" standard for bariatric surgery.
Gastric bypass may be performed open or laparoscopically. For very obese patients (those with a BMI of 50 or greater) surgeons may prefer the open approach. For patients with a lower BMI, either approach may be medically appropriate. Each approach has advantages.