Gastric Bypass is an established technique for control of obesity. The US National Institutes of Health described Gastric Bypass as the “Gold Standard” operation in the consensus conference of 1991. Early results of 60–80% excess weight loss are observed and there are 14 year figures of around 50% indicating this loss is sustained.

The technique involves creating a 15–20 cc gastric pouch with the distal stomach left in situ. A long (75–100cm) Roux loop passes retrocolic or antecolic to the enteroanastomosis.

Laparoscopic techniques developed since 1995 have involved a reexamination of the methods with a number of different approaches used in different centres. The procedure is being developed in centres in Australia and New Zealand.

In the USA, an estimated 103,000 operations were performed in 2003, 56% of these were performed laparoscopically and a large proportion of these were gastric bypass.

Open gastric bypass can be a technically demanding procedure, and laparoscopic Roux Y bypass can be formidable. As revisional surgery, the technical difficulty is increased as is the complication rate.

In the Australian context, the gastric bypass is indicated for super obesity, failure of restrictive surgery, and patient request. Despite its popularity and clear medium term results Gastric banding in its present form has only been available for 10 years and its longer term results have not been established. Laparoscopic gastric bypass, despite its steep learning curve, may offer reliable reduction of obesity related comorbidity.