The Roux-en-Y gastric bypass (RGB) is the most commonly performed weight-loss operation all over world. It involves removing part of the stomach and small intenstine to allow less food to enter the body and also inhibits absorption of calories and nutrients.
A Roux-en-Y stomach bypass can be performed laparoscopically or by using open surgery. The procedure has three basic variants, depending on the length of intestine bypassed. Proximal RGB involves very little malabsorption of calories and nutrients. Medial RGB causes moderate malabsorption. And distal RGB causes significant malabsorption.