Bariatric surgery can be done in several ways. This type of bariatric surgery, called biliopancreatic diversion with duodenal switch (BPD/DS), changes the size of your stomach and the length of your small intestine. The goal is to limit how much food can be eaten and absorbed at one time. During this type of procedure, part of the stomach is closed off with staples to create a smaller pouch. The remainder of the stomach is removed. This smaller stomach restricts the amount of food you can eat at one time. The small intestine is then divided, and only a very short length of its lower portion is reattached to the stomach pouch. Because part or most of the small intestine is bypassed, less water and fewer nutrients from food are absorbed.