The operation called Gastric bypass surgery involves the creation of a smaller stomach to restrict the amount of food that can be eaten.
The digestive system is also rerouted to decrease the ability to absorb calories and nutrients from food. This operation takes a number of forms but the most common is the Roux-en-Y gastric bypass surgery. This is where a small stomach pouch is created by stapling part of the stomach together. Next, a Y-shaped section of the small intestine is attached to the pouch to allow food to avoid the duodenum.
Open gastric bypass surgery usually take 90-120 minutes but if a keyhole procedure is chosen it may take up to twice as long to perform. Three quarters of patients are expected to lose 75 to 80% of their excess body weight. Most of this excess is lost in the first two years following the operation. However, doctors advise that it should not be thought of as a guaranteed cure for obesity. A well balanced diet - together with appropriate physical activity - remains important afterwards.
One possible unwanted side effect is that the operation, along with reducing the uptake of calories, may also reduce the absorption of important vitamins and minerals such as iron, vitamin B-12 and calcium. This can have important health implications and patients are often recommended to take a daily vitamin and mineral supplement. 'Dumping syndrome' - characterised by abdominal cramping and diarrhoea after eating food with a high sugar content - can also occur.
Any procedure of this nature carries a measure of risk which should be thoroughly discussed with your doctor so that you understand all the details.