Gastric Bypass

Laparoscopic Gastric Bypass

Gastric bypass is a restrictive weight loss procedure that is performed in people with a BMI of 40 or more. This procedure has been performed in Europe and the United States for more than 20 years and is rapidly gaining popularity in Australia and the United Kingdom.

The gastric bypass is essentially a restrictive gastric procedure.

The principal of the gastric bypass is quite straight forward and has two components:

The first is for the surgeon to dramatically reduce the stomach volume using a special cutting and stapling technique. The very top of the stomach is converted into a 30-50ml pouch. This creates a very restricting effect as it dramatically reduces the volumes of foodstuffs that can be tolerated.

The second component is where the small stomach pouch is connected to a segment of the small intestine. This creates a small degree of malabsorption of calories as the foodstuffs are directed away from the digestive juices in the top part of the small intestine.


The gastric bypass usually provides quite emphatic and durable weight loss that has been proven in the medical literature to last for many years. Overall, we expect to see 60-70% excess weight loss.

Gastric bypass can be performed laparoscopically in some individuals, but in others will involve laparotomy and opening of the abdominal cavity for safe completion. From the patient’s point of view, the advantages of this operation are that it provides fixed gastric restriction which does not require adjustment and usually permits fairly normal foodstuffs to be eaten but in very limited quantities. It has additional benefits in patients with diabetes in that these people will almost always have greatly reduced or no insulin requirements after the surgery.