Gastric Bypass surgery is the most common form of weight loss surgery. Gastric bypass is still considered the gold standard of weight loss surgeries. It is performed via a laparoscope and includes creation of a small gastric pouch of only 15-20 ml. The procedure involves approximately 5 small incisions and takes about 1 ½ hours. It bypasses the upper part of the intestine the duodenum, by rerouting the intestine through a connection called a Roux intestinal limb. There are multiple mechanisms of weight loss for this bypass. They include decreasing calorie intake through a smaller stomach, hormonal by increasing your metabolism, and lastly by decreasing the amount of calories you absorb. Expected weight loss averages around 75% excess weight loss over 2 years with the average of 60% excess weight loss over 10 years. The gastric bypass is the most studied operation with multiple studies showing the improvement in weight related health conditions as shown below.

The risks involve a leak, stricture, vitamin deficiencies, marginal ulcer, internal hernia and regain of weight.