Roux-en-Y gastric bypass (RYGB) is a type of weight-loss surgery that involves creating a small pouch from the stomach and connecting the newly created pouch directly to part of the small intestine called the Roux limb, forming a "Y" shape. This surgery reduces the size of the upper stomach to a small pouch about the size of an egg, which reduces the amount of food a person can eat. RYGB is a restrictive-malabsorptive operation performed for weight loss in individuals with a BMI of 40 or greater, or in those with a BMI of 35 or greater with obesity-related comorbidities. The surgery can be performed laparoscopically (small incisions to the abdomen) or robotically (computer-assisted surgery used to aid in surgical procedures). The specifics of the surgery depend on the individual situation and the doctors practices. The surgery promotes weight loss in two ways: by reducing the amount of food a person can eat and by reducing the amount of calories and nutrients the body absorbs from food.