Roux-en-Y gastric bypass

This figure depicts the stomach's appearance after Roux-en-Y gastric bypass, which creates a small stomach pouch by dividing the stomach and attaching it to the small intestine. The pouch is only able to hold about an ounce of food, causing a feeling of fullness after consuming a very small amount; over time, the pouch stretches to hold about one cup. In addition, the body absorbs fewer calories since food bypasses the majority of the stomach as well as the upper small intestine (duodenum). This intestinal arrangement (Roux-en-Y) seems to cause decreased appetite and improved metabolism by changing the release of various hormones.