of the production of the hunger hormone, ghrelin, is removed with the greater curvature of the stomach. The summarized data can be found on a poster: comparative poster Diet following the DS is more normal and better tolerated than with other surgeries. The malabsorptive component of the DS is fully reversible as no small intestine is actually removed, only re-routed. Disadvantages The malabsorptive element of the DS requires that those who undergo the procedure take vitamin and mineral supplements above and beyond that of the normal population, as do patients having the RNY surgery. Commonly prescribed supplements include a daily multivitamin, calcium citrate, and the fat-soluble vitamins A, D, E and K. Because gallstones are a common complication of rapid weight loss following any type of weight loss surgery, some surgeons may remove the gall bladder as a preventative measure during the DS or the RNY. Others prefer to prescribe medication to reduce the risk of post-operative gallstones. Like RNY patients, DS patients require lifelong and extensive blood tests to check for deficiencies in life critical vitamins and minerals. Without proper follow up tests and lifetime supplementation RNY and DS patients can become ill. This follow-up care is non-optional and must continue for as long as the patient lives. DS patients also have a higher occurrence of smelly flatus and diarrhea, although both can usually be mitigated through diet, including avoiding simple carbohydrates. The restrictive portion of the DS is not reversible, since part of the stomach is removed. However, the stomach in all DS patients does expand over time, and while it will never reach the same size as the natural stomach in most patients, some stretching does occur. Risks All surgical procedures involve a degree of risk however this must be balanced against the significant risks associated with severe obesity. Some of the surgical risks or complications for this procedure are: perforation involving small bowel, duodenum, or stomach causing a leak, infection, abscess, deep vein thrombosis (blood clot), and pulmonary emboli (blood clot traveling to the lungs). Longer term risks include the possibility of vitamin and mineral deficiency, hernia and bowel obstruction. There is little information as to the longer-term risks (greater than 15 years), as this procedure was very rarely performed prior to the year 2000. The traditional biliopancreatic diversion with duodenal switch (BPD-DS) led to persistent malnutrition in a subset of patients. However, the loop duodenal