Gastric bypass surgery: the advantages, procedure and potential risks

Gastric bypass surgery is a form of weight loss surgery that reduces your stomach by bypassing part of your digestive system. This restricts the appetite of the patient, allowing them to lose weight. The operation is done as a laparoscopic (keyhole) surgery procedure while the patient is under general anaesthetic. It usually takes between one and three hours. Patients tend to lose 60-70% of their excess body weight with a gastric bypass, more than with the gastric band or sleeve gastrectomy.

Gastric bypass surgery

Firstly, a small pouch is created at the top of your stomach using staples. A piece of your intestine is then joined to this gastric pouch. This bypasses the rest of your stomach and the upper part of the intestine, where most nutrients and calories are usually absorbed.

The new pouch at the top of the stomach fills up quickly with food, restricting the patient’s appetite. The food then travels straight to the middle part of your small intestine and through the rest of your digestive system. As the digestive system has effectively been made shorter, fewer calories are absorbed.

The bypass surgery can be performed as a standard open surgery, or as a laparoscopic surgery. The laparoscopic approach involves five or six very small incisions and has many advantages over open surgery, including quicker recovery, shorter hospital stays and a significantly reduced risk of infection.

What are the risks of gastric bypass surgery?

Gastric bypass surgery is generally safe, though, as with any operation, there are risks which patients should be aware of. These will differ from patient to patient but overall there is a 2-5% risk of adverse effects (many of which are those associated with any operation such as infection and risks associated with having a general anaesthetic) and a 0.5% risk of death. Typical side-effects are likely to include some bruising, pain and swelling.

In the long term, restricted diet may cause nutritional deficiency, vitamin and mineral supplements may need to be taken indefinitely.