Gastric Bypass

Gastric bypass surgery, also referred to as 'Roux-En-Y Gastric Bypass', is a surgical technique to assist seriously obese patients (ie BMI of more than 40) lose weight.

In the procedure, which is normally carried out using a laparoscopic or 'minimally invasive' approach, the existing stomach is stapled to produce a small pouch with a significantly smaller volume than the whole stomach (typically the new pouch has a capacity of around 15-20 cubic centimetres). Once this has been created, a section of the small intestine is connected directly to the pouch, which permits food to 'bypass' the lower part of the stomach and the first two sections of the small intestine (the duodenum and the jejunum). Once this procedure is complete, there is a reduction in the caloric intake.

The procedure itself involves making 4-6 small incisions in the abdomen and inserting laparoscopic instruments through these 'ports' to perform the surgery described above. The procedure normally takes 2-4 hours and is conducted under a general anaesthetic and necessitates a short stay in hospital afterwards, normally 2-4 days.

After surgery only puree foods or liquids can be consumed for 2-3 weeks, with solid food introduced only gradually. This is mainly to avoid stretching the small stomach pouch. Weight loss can be fairly rapid during the first six months, and a lack of protein in the diet during this period may cause body aches and feeling cold and fatigues. These symptoms should decrease and disappear as the body gets used to the change in diet. There is also a condition known as 'dumping syndrome' if larger quantities of food or sugar are eaten, which can cause nausea and weakness, and sometimes diarrhoea.

Unlike other weight surgery options (e.g. lap banding), a gastric bypass is a permanent treatment, that is, it is not reversible, however it is a technique that has a long track record of success and generally results in greater weight loss than other surgical approaches - over 70% of excess weight lost in the first year in most cases, with up to 50% weight loss maintained at the ten-year mark after surgery.

The disadvantages of gastric bypass surgery are that recovery after the surgery is longer than other surgical approaches and that nutritional and mineral supplements will be required on an ongoing basis after surgery.