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Gastric Bypass Surgery Overview

Gastric bypass is considered by many surgeons to be the ‘gold standard’ operation for morbid obesity and is commonly done worldwide. It is the operation with which all other weight loss procedures are compared.

Gastric bypass is a more technically challenging procedure to perform than other surgical procedures available but for most people recovery time and risk is similar to the sleeve gastrectomy (also known as the gastric sleeve). It has grown in popularity because it produces sustainable long-term weight loss in most patients, and many problems associated with obesity such as diabetes and sleep apnoea are improved or completely resolved.

The gastric bypass procedure involves creating a very small pouch out of the stomach and attaching it directly to the small intestine, bypassing most of the stomach and the first part of the small bowel. This small stomach pouch cannot hold large amounts of food, and by skipping the first part of the small bowel, hormones that control our appetite and food absorption are also affected. Together, this results in significant and sustained weight loss. This additional hormonal effect makes it a particularly effective operation for diabetes and other metabolic complications of obesity.

After surgery, patients start on liquids before moving to a pureed diet while the stomach heals. Several weeks after gastric bypass surgery patients progress to eating three small meals a day of normal consistency food. Entree-sized meals are enough to produce a sensation of fullness, making it easier for patients to limit the amount they eat.

Gastric bypass is now routinely done by laparoscopic (keyhole) surgery, which involves several very small incisions, rather than by open surgery, which uses one large incision. Harmless CO2 gas is introduced into the abdomen, inflating it, and creating a space for the surgeon to work. The surgeon introduces a long narrow camera and surgical instruments to perform the procedure.

Laparoscopic procedures have the advantages of less pain and shorter hospital stay and recovery, as well as significantly reduced risks of wound infection or hernias. If, for some reason, your surgeon cannot complete the procedure laparoscopically, he can switch safely to the open procedure. The chance of this happening is low and would only be done in your best interests.

Improved Health

Gastric bypass reduces the risk of death from obesity. Many obesity-related conditions, such as type II diabetes, obstructive sleep apnoea, joint pain from arthritis, high cholesterol and high blood pressure, are either completely resolved or substantially improved.

Long-term weight loss

Most patients achieve good to excellent weight loss results following gastric bypass surgery; typically this is 65-75 per cent of excess weight. Patients lose most of their weight in the first 12 to 18 months, before their weight stabilises. There can be some weight regain after this time, but it is usually minor. There is no amount of weight loss that is guaranteed.

Healthy lifestyle changes, with better diet and regular exercise, lead to a better outcome after the surgery. Gastric bypass is best seen as a tool that makes these lifestyle changes achievable for most patients.


Anaesthesia for surgery →

Obesity surgery permanently changes how you can eat and it’s a process that needs to be carefully managed.