The procedure works in two ways, volume reduction and impaired absorption. The small gastric pouch has a restrictive effect thus limiting the amount of food that is eaten. The portion of intestine that is bypassed is not available for absorption or digestion, therefore the amount of calories and nutrients absorbed is reduced. The stand out feature of gastric bypass is that the pouch is compartmentalized and the procedure is therefore reversible. Patients typically can lose between 60-70% of EWL and particularly good results have been seen in patients with insulin-dependent diabetics.
In this procedure, the stomach is divided to create a small gastric pouch. Next a Y-shape section of intestine is joined to the gastric pouch. Food is then allowed to bypass the lower stomach and move directly into the intestines.
In this procedure, a longer gastric pouch is formed and a single loop of intestine is joined to the gastric pouch further downstream