Roux-en-Y Gastric Bypass (RGB): This operation is the most common and successful combined weight loss surgery in the United States. First, the surgeon creates a small stomach pouch to restrict food intake. Next, a Y-shaped section of the small intestine is attached to the pouch to allow food to bypass the lower stomach, the duodenum (the first segment of the small intestine), and the first portion of the jejunum (the second segment of the small intestine). This reduces the amount of calories and nutrients the body absorbs. Rarely, a cholecystectomy (gall bladder removal) is performed to avoid the gallstones that may result from rapid weight loss. More commonly, patients take medication after the operation to dissolve gallstones.
Advantages of this weight loss surgery:
greatly controls food intake, leading to rapid weight loss
dumping syndrome dumping conditions to control intake of sweets
reversible in an emergency though this procedure should be thought of as a permanent
Disadvantages of this weight loss surgery:
staple line failure
ulcers
narrowing/blockage of the stoma
vomiting if food is not properly chewed or if food is eaten to quickly
weight re-gain is known to happen if dietary changes are not followed long term