Gastric bypass surgery is one type of procedure that can be used to cause significant weight loss if you are very obese. The surgery reduces your body's intake of calories. Calorie reduction is accomplished in two ways:
1. After the surgery, your stomach is smaller. You feel full faster and learn to reduce the amount that you eat at any given time. 2. Part of your stomach and small intestines are literally bypassed (skipped over) so that fewer calories are absorbed.
What Types of Gastric Bypass Operations Are There?
Roux-in-Y gastric bypass (RGB). This operation is the most common gastric bypass procedure performed. First, a small stomach pouch is created by stapling part of the stomach . This limits how much food you can eat. Next, a Y-shaped section of the small intestine is attached to the pouch to allow food to bypass the duodenum as well as the first portion of the jejunum. This causes reduced calorie and nutrient absorption.
Gastric bypass operations that cause malabsorption and restrict food intake produce more weight loss than restriction operations, which only decrease food intake. People who have bypass operations generally lose two-thirds of their excess weight within 2 years.