The Single Loop Gastric Bypass (Mini Gastric Bypass) procedure is commonly performed by the BodyFree Surgeons. We have seen terrific results with our patients, with weight loss goals achieved. We offer a fixed fee Gastric Bypass program from $3,990 for insured patients. Fixed fee programs are available for uninsured patients from $16,500. Call us on 9565 5505 to start your Weight Loss Surgery journey.

Single Loop Gastric Bypass is also known as Mini Gastric Bypass, Omega Loop Gastric Bypass or Single Anastomosis Gastric Bypass.

Single Loop Gastric Bypass, Mini Gastric BypassThe Single Loop Gastric Bypass may be less familiar than the more commonly performed Roux-En-Y Gastric Bypass procedure, however, it has begun to be used more frequently in the treatment of Obesity and has been shown to deliver very similar weight loss results.

The Single Loop Gastric Bypass procedure involves a reduction in the size of the stomach to a tubular (or pouch) shape which is then connected directly to the upper intestine for nutrient absorption. The stomach pouch bypasses a large portion of the stomach, and upper intestine, creating a smaller space that limits the amount of food that can be consumed, allowing patients to feel fuller faster, and reduces the absorption of nutrients. With Single Loop Gastric Bypass, weight loss occurs as a result of both malabsorption and a reduction of food intake.

There is evidence to suggest the Single Loop Gastric Bypass offers better diabetes control. Some patients who suffer from problematic reflux symptoms may do better with a classical Roux-en-Y Gastric Bypass.

Single Loop Gastric Bypass Surgery Pros and Cons


  • Excellent long-term weight loss success and maintenance.
  • Reduced risk of complication when compared to the alternative Bypass method due to reduced intestinal joins required (with a loop rather than ‘y’ shaped join).
  • Patients with poorly controlled Diabetes or Dyslipidaemia (high cholesterol) are more likely to see improvements in these conditions following a Single Loop Gastric Bypass.


  • There is a risk of nutritional deficiencies following surgery due to reduced absorption and food intake. Supplements may be required.
  • Female fertility may be improved, but there is a slightly increased risk of underweight or pre-term births.
  • Some patients may experience Dumping Syndrome which can result in new intolerances to certain foods.

Single Loop Gastric Bypass Pre-Operative Care

In order to provide a safe and successful procedure, recovery period and outcome – Single Loop Gastric Bypass surgery requires a dietary change in preparation for the procedure.

BodyFree patients are placed on an Optifast based diet for a period of 2-3 weeks prior to surgery. This diet changes the patient’s metabolism putting them into Ketosis resulting in the burning of fat stores in the body (and in particular in the liver). This enables safe retraction of the liver during surgery without the risk of tearing or damage to that organ.

While on the Optifast diet, the consumption of carbohydrates, sugars, fruits or juices etc.  are not permitted.  Our Dietitian will provide clear instructions on what foods may be consumed during this period.

The good news about this pre-op diet is that some patients note that they lose 5-10% of their body weight during the period – an encouraging start to their weight loss journey.  Unfortunately these results are not maintainable over the long term with Optifast only sustainable for a short period of time.


The majority of medications can continue to be taken until the day of surgery, however there are several blood thinners and anti-platelet agents that must not be taken 2-10 days prior to surgery. Your surgeon will discuss this with you and provide direction here.  Medications can be re-commenced following surgery under our direction.

Please note fish oil supplements should not be taken within 14 days of surgery.

Single Loop Gastric Bypass Post-Operative Care

Wound Care

Following your laparoscopic procedure, the small keyhole incisions are closed with dissolving stitches that are not visible as they are placed under the skin. Steristrips and water proof dressings are placed on the skin surface to ensure the skin heals in a clean and dry environment. The water proof dressings allow for patients to bathe or shower normally with dressings requiring a pat dry afterwards.

The dressings should remain in place for 7-10 days after surgery at which time the incisions should have healed nicely.

Pain Management

Any discomfort felt immediately post-surgery will be managed as an inpatient in hospital. At the time of discharge from hospital most post-operative pain has subsided. Some patients may need a small amount of medication to help manage continuing discomfort for a week or so. Possible medications prescribed include Panadol, Panadeine Forte or Endone.

Other Medicines

Pre-prescribed medications can be recommenced as directed by your surgeon in the post operative phase and any blood thinning agents that patients were previously taking will also be recommenced as directed by the medical team.

Many patients will be directed to take a PPI (Proton Pump Inhibitor) such as Nexium, Somac or Losec for a certain period after surgery to reduce stomach acid production.

Post-Operative Diet

Following Single Loop Gastric Bypass surgery, dietary and behavioural changes are necessary in order to achieve successful long term results.

Patients will be given specific dietary advice tailored to them based on their personal requirements, but the following are very brief recommended guidelines following surgery.

Week 1

  • Liquid nourishment

Weeks 2 – 4

  • Pureed food

Week 4 +

  • Commencement of soft solid diet.

** For more dietary information, please speak with your Dietitian, who will provide you with a more comprehensive plan.

Recovery Time

As a general guide, patients need 2-3 nights in hospital following Gastric Bypass surgery, and anywhere from 3-14 days off work depending on the physicality of your role. Most patients can start walking within a few days, and more vigorous exercise within 3 weeks. During your post-operative visit, your surgeon will be able to provide guidance on the level of exercise you may perform following surgery.