What is a Single Loop Gastric Bypass?
Mini Gastric Bypass
Single Loop Gastric Bypass assists with weight loss as a result of both malabsorption and a reduction of food intake.
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. This ensures patients feel fuller faster, as well as reducing the absorption of nutrients to cut down on calorie intake.
Single Loop Gastric Bypass vs Roux-en-Y Gastric Bypass
The Single Loop Gastric Bypass may be less familiar than the more commonly performed Roux-En-Y Gastric Bypass procedure. However, the Single Loop is now being used more frequently for the treatment of obesity and management of obesity-related health conditions. This form of Gastric Bypass has been shown to deliver equally positive weight loss results as a Roux-en-Y.
Single Loop Gastric Bypass works the same way as its Roux-en-Y counterpart. Both result in a stomach pouch with a reduced volume, thereby helping you feel full much more quickly. The key difference is that it creates a smaller amount of intestinal re-routing, assisting in effective weight loss surgery with minimal risk of complications.
The key difference between the standard Roux-en-Y Gastric Bypass and the Single Loop Gastric Bypass is that it creates a smaller amount of intestinal re-routing. The procedure regularly assists in successful weight loss surgery, with minimal risk of complications.
Who Should Consider the Single Loop Gastric Bypass?
There is evidence to suggest the Single Loop Gastric Bypass offers better diabetes control. Some patients who suffering from problematic reflux symptoms may do better with a classical Roux-en-Y Gastric Bypass.
BEFORE AFTER
GASTRIC BYPASS SURGERY GASTRIC BYPASS SURGERY
Pros
- Patients with poorly controlled diabetes or dyslipidemia (high cholesterol) are more likely to see improvements.
- A lower risk of complication when compared to Roux-en-Y gastric bypass This is due to reduced intestinal joins, with a loop rather than Y-shaped join.
- Excellent long-term weight loss success and maintenance.
Cons
- There is a risk of nutritional deficiencies following the surgical procedure due to reduced absorption and food intake. Supplements may be prescribed.
- Female fertility may be improved, but there is a potential risk of underweight or preterm births.
- Some patients may experience dumping syndrome, which can result in new intolerances to certain foods.
To find out more about the Single Loop Gastric Bypass, contact our Bariatric Surgery team now.
Mini Gastric Bypass Pre-Operative Care
In order to provide a safe and successful procedure, recovery and outcome, Mini Gastric Bypass patients at our Sydney clinic require a dietary change in preparation for the procedure. Medications and supplements may need to be altered prior to surgery as directed by our bariatric surgeons.
Diet
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.
Ketosis results 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 the organ.
While on the Optifast diet, the consumption of carbohydrates, sugars, fruits and juices is not permitted. Our specialist Dietitians 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 will lose 5-10% of their body weight in this period – an encouraging start to their weight loss journey! Unfortunately, these results are not maintainable over the long term, as Optifast is only sustainable for a short period of time.
Medication
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 Mini Gastric Bypass surgeon will discuss this with you and provide direction.
Medications can be re-commenced following surgery under our direction, but fish oil supplements should not be taken within 14 days of surgery.
Mini Gastric Bypass Post-Operative Care
Wound Care
Following your laparoscopic procedure, the small keyhole incisions are closed with dissolving stitches. These are not visible as they are placed under the skin. Tissue glue or Steristrips and waterproof dressings are placed on the skin surface to ensure the skin heals in a clean and dry environment.
The waterproof dressings allow for patients to bathe or shower normally, with dressings requiring a pat dry afterward. 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 the hospital. At the time of discharge from the hospital, most postoperative 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 postoperative phase. 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 to achieve successful, long-term results.
Patients who have had a Single Loop, also known as Omega Loop Gastric Bypass, will be given specific dietary advice, tailored to them based on their personal requirements. The following are very brief recommended guidelines for a post-operative diet.
Week 1
- Liquid diet
Weeks 2 – 4
- Pureed food
Week 4 +
- Soft solid diet
** For more dietary information, please speak with your BodyFree Dietitian, who will provide you with a more comprehensive plan.
Recovery Time After Single Loop Gastric Bypass
We recommend scheduling a period of recovery time to ensure that you fully heal. As a general guide, we recommend 2 nights in hospital following Omega Loop Bypass, 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 guide you on the level of exercise you may perform following surgery.

Mini Gastric Bypass surgery at our Sydney clinic can transform your quality of life and deliver long-term health benefits. Contact BodyFree today for a consultation.
Single Loop Gastric Bypass Surgery can transform the quality of your life. Contact BodyFree today.
Frequently Asked Questions
Can a Single Anastomosis Gastric Bypass be reversed?
This procedure is reversible, however, performing this type of surgery can be quite complex with surgeons considering the risks against the benefits. Reversal of the Mini Gastric Bypass procedure is considered only for patients who have more significant complications following surgery such as severe malnutrition, chronic ulcers, or sugar management problems.
How much weight can I expect to lose with this procedure?
Studies reveal that a Single Anastomosis Gastric Bypass procedure can achieve an excess body weight loss of 60% to 80% within the first year or two. Actual results may vary based on factors like the patient’s body type.
Who is eligible for the procedure?
Similar to other bariatric surgery procedures, Single Loop Gastric Bypass is appropriate for people with a body mass index (BMI) of 35 or above. Individuals with a BMI of 30-34 are also acceptable if they suffer from major obesity-related complications such as diabetes.
Is a Single Loop Gastric Bypass more effective than other procedures?
All weight loss surgery procedures are effective, deciding on the best procedure for you is the key.
The best way to make this decision is to consult with a bariatric surgeon. Contact us to arrange an appointment to learn which bariatric procedure would be the best to help you achieve your health and lifestyle goals.