Weight Loss Surgery

Gastric Bypass

Gastric Bypass

This is a combined restrictive and metabolic procedure. The top of the stomach is divided to create a small pouch. The small bowel is divided and then reconstructed to allow food to pass directly to the small intestine bypassing most of the stomach and the duodenum. The bypass component alters the level of various gut hormones normally produced in the duodenum which controls how the body processes and metabolises food.


  • Highly effective for weight loss and diabetes
  • Effectively stops bile and gastric reflux
  • Discourages eating sugar and fats which cause “dumping syndrome”


  • More complex surgery with higher risks
  • Mild malabsorption which requires lifelong nutritional supplementation and annual screening blood tests to prevent vitamin and mineral deficiency
  • Potential for anastomotic stricture, ulcers, pouch dilatation
  • Small future risk of internal hernias causing bowel obstruction which can require emergency surgery and may be life threatening
  • Further revision surgery is difficult with limited options


  • 70% average excess weight loss at 1-2 years

Current Status (2013):

Although Gastric Bypass has been the most popular bariatric procedure in the Northern Hemisphere for the last decade, more recent data demonstrates that Sleeve Gastrectomy can achieve similar outcomes with lower risks and has therefore been our preferred primary procedure.

We believe Gastric Bypass is still a useful option to consider for patients with difficult to control diabetes, uncontrolled gastro-oesophageal reflux or as a revisional procedure.

Read the next page about Gastric Banding

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