The Roux-en-Y (roo-en-y) gastric bypass is the bariatric surgery procedure done most often. The word “gastric” means stomach. This bypass surgery decreases the amount you can eat and drink at one time and reduces the nutrients your small intestine absorbs. It is named for the surgeon who first described it and for the Y shape of the intestines after the surgery.

You surgeon divides your stomach into two parts – a small, upper part, and the remaining lower part. The smaller part is called the gastric pouch. It is about the size of walnut and holds only about one tablespoon of food.

Your surgeon cuts your small intestine and connects the lower part to the gastric pouch. The upper part of your small intestine that is still attached to the rest of your stomach is called the bypassed segment. Your surgeon connects it to the middle of your small intestine. Your intestines now form a “Y”

When you eat and drink, food and fluids enter the gastric pouch and then mc into the small intestine connected to it. Juices that digest food drain from the large, lower part of the stomach through the bypassed segment. They enter the middle part of your small intestine where they mix with the food you have eaten. The rest of your small intestine absorbs nutrients and calories as food moves through it. Because food passes by most of your stomach and the first part of your small intestine. Your body absorbs fewer calories and nutrients.