Gastric bypass is the commonest form of malabsorptive operation performed.

With a gastric bypass, the stomach is stapled across the top to form a small pouch which will allow you to eat only a tiny amount of food before feeling full. Food leaves this tiny stomach pouch into a segment of small intestine which is created by dividing the bowel further down and then re-attaching it to the stomach pouch. If you eat food that contains sugar or fat this section of intestine reacts by creating symptoms of nausea, sweating and diarrhoea known collectively as dumping syndrome. Although not dangerous, it is unpleasant enough to lead people to avoid such high calorie foods.

Bypassing part of the intestine means that valuable nutrients are not absorbed and so life-long daily supplements are required.

Initial weight loss may be more rapid with a gastric bypass than with a gastric band although long term results of either technique are similar.  People who undergo gastric bypass can expect to lose at least 60% of their excess weight and many obesity-related illnesses improve significantly, including type 2 diabetes.  There is an increased risk of serious complications at or around the time of surgery when compared to gastric banding.  The gastric bypass operation is not fully reversible.

All surgery is associated with some risk. The Weight Loss Surgery Clinic will provide you with full information about the specific risks of this type of surgery.