Nutrition and gastrointestinal complications of bariatric surgery.

At present, bariatric surgery is the only treatment that can achieve meaningful and sustainable weight loss for the millions of morbidly obese individuals. The current popular operative procedures (the Roux-en-y gastric bypass, laparoscopic adjustable gastric band, and the biliopancreatic diversion with or without duodenal switch) are all relatively safe and effective. However, all of these procedures, to variable degrees, alter the anatomy and physiology of the gastrointestinal tract. This fact, along with postoperative dietary changes, makes these patients vulnerable to a multitude of potential complications. As more and more patients undergo these procedures, an increasing number of clinicians will be asked to care for them. It is therefore imperative that all clinicians have a general understanding of the operative procedures and the potential problems these patients may develop. This article will describe these operative procedures and will discuss the more common consequences.