Roux-en-Y Gastric Bypass, RNY BypassRoux-en-Y Gastric Bypass Surgery has been very popular overseas for many years and can result in excellent long-term sustained weight loss. This Weight Loss Surgery procedure is performed using a few small laparoscopic (keyhole) incisions, and creates a small portion of narrow stomach which is disconnected from the rest of the stomach. Some small intestine is then brought up to join this now smaller piece of stomach allowing the ingested food to “bypass” the majority of the stomach, and the first 1-2 metres of small intestine (most people have 4 metres or more of small intestine).

Gastric Bypass surgery works by combining both restrictive and malapsorptive methods. By reducing the physical size of the stomach patients become fuller faster so are therefore likely to eat less, while the “bypassing” of a section of the intestine means the absorbtion of calories and nutrients consumed is reduced.

The BodyFree team currently considers the Gastric Sleeve (Sleeve Gastrectomy) to be a superior solution when taking into account quality of life issues combined with excellent weight loss results. There are however circumstances when we might recommend a Gastric Bypass. We would consider this type of procedure if you had poorly controlled Type II Diabetes Mellitis. There is evidence to suggest the Single Loop/Mini Gastric Bypass offers better diabetes control, however some patients who suffer from problematic reflux symptoms may do better with a classical Roux-en-Y Gastric Bypass. We would also consider using a Gastric Bypass as a solution for patients who come to see us for a revision from a prior Bariatric surigical procedure, such as a Gastric Band, or a Gastric Sleeve/Sleeve Gastrectomy.

Roux-en-Y Gastric Bypass Surgery Pros and Cons


  • Excellent weight loss success and long-term maintenance.
  • Ideal for very poorly controlled Diabetes or Dyslipidaemia (high cholesterol).


  • At risk of medium to long-term nutritional deficiencies, so may need some vitamin and nutritional supplements long-term.
  • Can improve fertility in women, but slightly increased risk of pre-term and underweight birth neonates.
  • Some patients may suffer from Dumping Syndrome resulting in an intolerance to certain foods.

Roux-en-Y Gastric Bypass Pre-Operative Care

All patients are required to commence an Optifast based diet for a period of 2-3 weeks prior to Gastric Bypass surgery. This diet induces a change to the patient’s metabolism putting it into a Ketotic state, known as Ketosis. During this period the patient’s diet will be restricted, with only certain additional foods allowed (your Dietitian will provide clear direction tailored to you). There are no carbohydrates, sugars, fruits or juices etc. permitted during this Optifast period.

The ketosis will result in fat stores coming out of the liver to provide the metabolic fuel your body needs. During surgery, it is necessary to retract the liver – the reduction in fat stores in the lead up to surgery allows for this to be done safely without risk of damaging or tearing the liver during the procedure.

Some patients may note that they can lose 5-10% of their body weight during this period. (It would be terrific if this were sustainable long-term, but Optifast isn’t sustainable over time).


Most medications can continue until the day of surgery, and they will be recommenced post-operatively under our direction. There are several blood thinners and anti-platelet agents which will need to be stopped 2-10 days prior to surgery depending on the particular medication. We will provide advice tailored to each patient. Fish Oil supplements should not be consumed within 14 days of surgery.

Roux-en-Y Gastric Bypass Post-Operative Care

Wound Care

The small keyhole incisions are all closed with dissolving stitches which are all placed under the skin so that patients will never need to see them. We also use steristrips and waterproof dressings to ensure the skin heals in a clean and dry environment. Patients can bathe or shower with these dressings in place, however they should be patted dry afterwards.

The dressings are normally removed 10 days after surgery and the incisions should have healed nicely by then.

Pain Management

Most patient’s post-operative discomfort has settled at the time of discharge from hospital. Some patients may however require a small amount of oral medication to help manage ongoing discomfort for a week or so. This can include Panadol, Panadeine Forte, Endone, or occasionally other medicines.

Other Medicines

Routine medications can be recommenced as directed 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

Surgery will help patients to start their weight loss journey, however, in order to achieve successful long-term results – dietary and behavioural changes are necessary.

Each patient will be given specific dietary advice based on their personal requirements, but the following are very brief recommended guidelines following Gastric Bypass 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 guide, most patients need 2-3 nights in hospital post-op, and depending on the work in which you are employed, anywhere from 3-14 days off work. Most patients can start walking within a few days, and more vigorous exercise can commence within 3 weeks.