Gastric bypass is a bariatric surgery technique included within the techniques considered mixed, because it is restrictive and selectively malabsorptive. Gastric bypass is a bariatric surgery that requires general anesthesia but it is not invasive and has a little painful after surgery.

It is restrictive because it considerably reduces the size of the stomach. And it is selectively malabsorptive because it alters the digestive cycle so that the intestine absorbs less fat and sugar. Both characteristics add up so that this technique achieves very satisfactory results in weight loss and in the improvement of diabetes, hypertension and other diseases associated with obesity.

Through this technique, and laparoscopically, the surgeon cuts the stomach leaving a small cavity of between 15 and 30 ml (known as a reservoir or pouch) while the rest is isolated so that food does not pass through. Another incision in the small intestine allows the surgeon to connect it directly to the small, newly created stomach. Thus, the food skips the stomach and a segment of the small intestine that surrounds the pancreas (origin of diabetes), so the body absorbs fewer calories and sugars.

In addition, with the reduction of the stomach that is done, a significant reduction in the production of ghrelin, the hunger hormone, is achieved. Thus, the patient loses weight effectively and has more options to maintain it in the long term by reducing the appetite and reducing the absorption of calories.