Gastric bypass, or gastric bypass surgery, is one of the techniques used in bariatric surgery, that is, to treat morbid obesity, and it is a mixed type procedure: restrictive and malabsorptive. It is a technique most used in the US and in other countries, due to its low morbidity and mortality, good long-term results, and excellent quality of life after surgery. The procedure consists of reducing and restricting the intake of food, creating a small reservoir along the lesser curvature of the stomach, separating it from the rest of the stomach to avoid a fistula effect, and a deviation to the small intestine in Roux-en-Y. This achieves an early satiety due to the restrictive component, and a malabsorption that adds efficiency to the technique.
With gastric bypass the degree of weight loss is variable and basically depends on the patient’s behavior after intervention, requiring an adequate diet and a supplementary exercise regimen.
Weight loss (between 50 to 75% of the initial excessive weight) usually occurs during the 6 to 12 months after the intervention, after which it tends to stabilize. If the patient does not follow the diet and exercise recommended by the doctor, he or she may regain part of the weight lost.