A gastric bypass is an irreversible procedure. It involves dividing the stomach into a smaller upper section, or ‘pouch’ and connecting the small intestine directly to that pouch. The result is that the ‘stomach volume’ is reduced, as is the length of effective small intestinal tract. 

Post-surgery, the patient therefore experiences a feeling of fullness after consuming less food since the pouch ‘fills’ up much faster than the previous, larger, stomach.

This is a procedure that the Tasmania Anti Obesity Surgery Centre performs in Hobart.

The procedure is mostly carried out laparoscopically, which is a procedure that is less invasive and commonly referred to as ‘keyhole’ surgery. The main benefits of this type of surgery being used to perform a complex procedure like a gastric bypass is that it is less stressful on the body, and thus recovery times are often faster (when compared to a non-laparoscopic procedure)

This type of weight loss surgery can lead to a 60-70% loss of total weight over a period of 24 months. Howeverit is vitally important that the patient adheres to all the advice, check-ups and necessary safety precautions for this to occur

This gastric surgery also reduces the absorption of nutrients into the body and so reduces the overall calorie intake; a primary catalyst for weight-gain. Unsurprisingly, limiting this intake leads to weight loss because the patient will tend to expend more energy in their daily lives compared to what they are ingesting. 

To supplement this need for energy, the body will look to burn its fat stores – hence weight loss.

Since this procedure is not reversible, long term nutritional/mineral supplements are required in order to avoid anaemia and vitamin deficiencies.

Residual stomach capacity: 30-50mls

Estimated weight loss: 60-70% EWL over 2 years.

Find out about more information on the obesity services provided at our Burnie, Launceston and Hobart clinics.


• “Dumping syndrome” if sweets and chocolates taken
• Good operation for sweet eaters
• Long track record
• Tend to lose a little more weight than gastric band


• Open surgery therefore increased risks
• Longer recovery time
• Permanent
• Not reversible
• Staple line leak
• Minor late weight regain 10-20% after 2-5 yrs
• Nutritional/ mineral supplements required