Gastric bypass surgery is a type of bariatric, or weight loss surgery offered at St George Obesity & General Surgery. During the procedure, your surgeon modifies the stomach and small intestine to change the way food is absorbed and digested.
This operation supports weight loss through three key mechanisms: it restricts the amount of food the stomach can hold, limits the calories and nutrients absorbed by the body and alters gut hormones that promote fullness, appetite control and improved metabolic health.
Gastric bypass is performed within a comprehensive program of assessment, surgery and long-term follow-up.
What does the procedure involve?
Here at St George Obesity & General Surgery, all bariatric operations are performed through keyhole surgery (laparoscopic or robotic) under general anaesthesia. There are two main types of gastric bypass procedures offered: the Roux-en-Y Gastric Bypass and the Mini Gastric Bypass.
During the procedure, Dr Qiuye Cheng (MED0001667801), our gastrointestinal and bariatric surgeon, makes five small incisions, each approximately one centimetre in length. A small stomach pouch is then created before re-routing the small intestine into a Y-shaped configuration (for Roux-en-Y Gastric Bypass) or a loop configuration (for Mini Gastric Bypass) to limit food intake and nutrient absorption. The bypass length typically ranges between 1.5 and 2 metres.
At the end of the procedure, the incisions are carefully closed with stitches. These small incisions may leave scars, which generally fade over time.
Who is an ideal candidate for gastric bypass surgery?
You may be eligible for the procedure if:
- Your body mass index (BMI) is greater than 40
- Your BMI is greater than 35 and you have a weight-related health condition, such as diabetes
- You have attempted other weight loss methods, including diet and exercise without achieving long-term success.
A thorough consultation with Dr Cheng is required to confirm your suitability for gastric bypass surgery in Sydney and to ensure it aligns with your health goals and medical needs.
Preparation and assessment
As part of the pre-operative preparation, you may be asked to complete several assessments, including:
- Blood and urine tests
- Chest X-ray and electrocardiogram (ECG)
- Gallbladder ultrasound
- Anaesthetic review
- Additional specialist tests — These may include pulmonary function testing, echocardiogram, sleep studies, gastrointestinal evaluation, cardiology review or psychiatric assessment.
You may be asked to start a pre-operative liquid protein diet two weeks before surgery. In addition, you’ll need to avoid eating or drinking after midnight on the night before your operation.
The day of the procedure
Gastric bypass surgery is performed under general anaesthesia, allowing you to remain fully asleep and comfortable throughout the procedure. As part of the standard surgical protocol, antibiotics and clot prevention measures will be administered to ensure your safety.
Afterwards, you’ll be taken to a recovery area until you’re fully awake. Antibiotics and clot prevention measures will be administered as part of the standard surgical protocol.
Recovery and aftercare
You will receive intravenous fluids immediately after surgery and continue until you are able to drink with ease. For the first two to six weeks after your operation, you will need to follow a liquid or soft food diet. Gradually, solid foods will be reintroduced, following the structured plan developed by your dietitian.
It’s important to follow the discharge instructions provided by your surgeon. This may include the following:
- Following your dietary plan, eating slowly and maintaining good hydration.
- Attending all scheduled follow-up appointments, where your progress, dietary advancement and overall health will be reviewed.
- Taking pain medication only as prescribed.
- Avoiding strenuous activities such as heavy lifting, cycling, jogging, weight training or aerobic exercise until cleared by your surgeon.
- Keeping your incision sites clean by gently washing them daily with warm, soapy water and patting dry.
- Covering the incision area with a clean gauze dressing, especially if it rubs against clothing or shows mild drainage. Replace the dressing each day or as directed.
Possible complications
While the gastric bypass surgery at St George Obesity & General Surgery is performed with the highest standards of safety and care, it’s important to be aware of potential complications:
- Bleeding, infection or clots in the legs or lungs
- Leakage along the staple line
- Reflux or heartburn
- Nutrient deficiencies
- Constipation, diarrhoea or gallstones
- Loose skin following major weight change
- Low blood sugar symptoms
- Increased stomach ulcer risk
- Requirement for further procedures such as endoscopy or revisional surgery
These potential risks and how they relate to your individual health will be discussed in detail during your consultation.
Book a consultation for gastric bypass surgery in Sydney
If you and your doctor are considering gastric bypass, we invite you to arrange a private appointment with Dr Cheng and the team at St George Obesity & General Surgery.
Recognised by the Surgical Review Corporation (SRC) as a Surgeon of Excellence, Dr Cheng provides an evidence-based, multidisciplinary approach focused on long-term weight management and patient wellbeing.
Each consultation is confidential and comprehensive. We’ll examine your medical history and explore appropriate treatment options for your unique needs. For additional information, explore our blog and patient FAQs.
Ready to Kick Start Your Weight Loss Journey?
If you’re considering gastric sleeve surgery in Sydney, our experienced team at St. George Obesity & General Surgery is here to help. Learn more about the procedure, explore our FAQs or book a consultation with Dr Cheng today. You can also read more about how to prepare for weight-loss surgery on our blog.
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