This operation is the most common and successful type of malabsorptive surgery. Malabsorptive operations restrict both food intake and the amount of calories and nutrients the body absorbs. They are also the most common gastrointestinal surgeries for weight loss.
First, a small stomach pouch is created 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 bypass reduces the amount of calories and nutrients the body absorbs.*