It refers to the ‘Y’ shape of the small bowel connection. During the operation, the small bowel is cut and then reconnected at one end to the newly created pouch (the new stomach) where it will now receive food that has been chewed and swallowed. None of the bowel is removed during the surgery. The new connection between the stomach pouch and the small bowel is called an anastomosis. This narrow opening helps restrict the passage of food moving from the pouch into this piece of small bowel, called the Roux limb (after a French surgeon, Roux). The Roux limb is the right arm of the “Y.” The left arm of the “Y” is the part of the bowel still connected to the excluded stomach. It carries the acids produced in the remnant stomach, the digestive juices produced by the liver and pancreas, including insulin, and some juices produced by the small bowel itself. The two arms of the “Y” are connected again.

Most patients stay two after laparoscopic gastric bypass and up to four days after open gastric bypass.