In Roux-en-Y gastric bypass surgery, the doctor cuts the top portion of the stomach and seals it off from the rest of the stomach to create a tiny pouch to control hunger and make calorie control possible. The pouch is then sewn into the lower part of the small intestine due to the fact that the food bypasses most of the stomach and the first part of the small intestine, leading to the consumption of smaller food portions.

It is a type of weight loss surgery that involves placing an inflatable band around the top part of the stomach, and the inflated band separates the stomach into two parts. The two divisions communicate through a thin channel created by the band, and a smaller stomach pouch means the person feels full faster and thus satisfies hunger while maintaining the right calorie intake. The band needs to be adjusted from time to time to regulate food movement.

This is a laparoscopic surgery wherein approximately 80% of the stomach is removed to create a smaller stomach pouch. The structure of the stomach after the surgery looks like a banana-like tube, leading to a drastic reduction in the consumption of food that results in rapid weight loss.

BPD/DS (biliopancreatic diversion with duodenal switch) is a less-common weight-loss technique that involves two primary phases. The first part of the procedure is similar to the gastrectomy wherein a smaller, tubular stomach pouch is created by removing a portion of the stomach. The second step involves bypassing a large portion of the small intestine, creating a switch.