At present there are three broad categories of bariatric procedures according to its mechanism of action: 1) purely restrictive, 2) primarily restrictive with some malabsorption, and 3) primarily malabsorptive with some restriction. Modern standard bariatric procedures recognized by the American Society for Metabolic and Bariatric Surgery "ASMBS" include the following 1) adjustable gastric band, 2) sleeve gastrectomy, 3) gastric bypass, 4) biliopancreatic diversion, and 5) duodenal switch.