How Much Is Gastric Bypass Surgery?

Gastric bypass prices vary depending on the individual and the surgeon’s discretion. A gastric bypass procedure is more complex than a gastric band, and the results are twofold (less food intake and less calorie absorption), so this is often reflected in the price. Private practitioners can charge anything in the region of £8,000 to £15,000 for a gastric bypass, making it the most expensive gastric procedure available.

Procedure Description Price Range (GBP)
Gastric Bypass A part of the stomach is sectioned and connected to the small intestine £8,000-£15,000
Gastric Band A band that divides the stomach and creates a smaller section £4,995-£9,000
Gastric Balloon A soft silicone balloon which is surgically inserted into the stomach £3,950-£6,000
Gastric Sleeve A portion of the stomach is removed, restricting the amount of food that can be eaten £8,000-£15,000

Gastric Bypass Surgery Through The NHS

mini gastric bypass

You may, however, qualify to have the procedure done on the NHS, although there are strict guidelines which your GP can tell you. Generally, most Primary Care Trusts require patients to have a BMI of over 40 or a serious health condition that can be improved with weight loss, to have tried all other non-surgical alternatives over at least a 6 month period and been unsuccessful, to commit to the long term lifestyle alterations and health plan, and to be able to withstand the surgery and the general anaesthesia. If you feel you meet these requirements, you should make an appointment to discuss your options with your GP.

For a rough idea of whether you might be entitled to NHS funding for your surgery then you can consult the weight loss section of the NHS website.

Who Is Suitable For Gastric Bypass Surgery?

Anyone whose body mass index is over 40 can be suitable for this procedure although they will have needed to try other options of losing weight first, such as diet and exercise. People who suffer from an illness such as high blood pressure or diabetes and have a BMI between 35 and 40 can also benefit from gastric surgery as this will often improve their condition.

Types Of Gastric Bypass Techniques Available

Traditionally there are three types of gastric bypass surgery available in the UK:

  • Mini Gastric Bypass: Otherwise know as a Loop Gastric Bypass this was the first use of the procedure using a small loop of bowel for reconstruction. Despite this being a simpler procedure than the two others available it was abandoned as a technique for weight loss due to the risk of enzymes from the Pancreas and Bile entering the esophagus from the bowel causing inflammation and ulceration in some cases.
  • Roux-en-Y (RGB): The most commonly used technique in Gastric Bypass procedures in the UK the Roux-en-Y entails a small pouch is created in the stomach through banding or stapling limiting it's capacity dramatically. Next a Y shaped segment of the small intestine is attached to allow any ingested food to bypass the a large part of the lower intestine (duodenum and jejunum).
  • Biliopancreatic Diversion (BPD): A far more complicated operation in which large parts of the stomach are removed and the final part of the smaller intestine is attached to the pouch of stomach that remains. Essentially this means that the majority of the smaller intestine is bypassed resulting in less absorption of any food ingested.

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How To Prepare For Surgery

In the lead up to your operation, your surgeon will provide you with some guidelines as to how to prepare. For example, they will ask you to abstain from drinking alcohol and smoking, as the latter greatly increases the risk of pulmonary embolisms and chest infections, and even infections affecting the incisions. You may also be prescribed a calorie-controlled diet that will help you lose weight ahead of your surgery. Normally a diet that’s low in fat, carbohydrates and refined sugars, this eating plan is designed to help you lose weight as this can greatly reduce the risk of complications during surgery.

If enough weight is lost, it could also mean the difference between open surgery and a keyhole procedure. Six hours before the surgery, you will need to fast so that there is nothing in the stomach during the procedure. If you are at risk of blood clots, your surgeon may ask you to wear compression stockings, and may prescribe a blood-thinner such as heparin in the run up to your gastric bypass.

How Is Gastric Bypass Surgery Performed?

During a gastric bypass, a surgeon makes your stomach smaller, and shortens the length of the small intestine to connect to this small pouch. The procedure is sometimes referred to as Roux-en-Y (“rou-en-why”), which is the most common method of gastric bypass in the UK. Ahead of the procedure, you will need to fast and refrain from both eating and drinking.

The operation will be carried out under a general anesthetic, and can take between one and three hours. The surgeon will start by making a small pouch at the top of the stomach, dividing it into two sections. Then, the small intestine is shortened and attached to this small pouch, creating a new digestive system. As the stomach is smaller, there is less capacity for food, and so patients eat less and therefore lose weight.

How Much Weight Can I Expect To Lose?

Watch Mr Chris Sutton, Consultant Specialist Bariatric Surgeon at Tonic Cosmetic Surgery, outline how much weight gastric bypass patients can expect to lose as a result of their surgery:


Video Transcript

"With a sleeve gastrectomy average weight loss is about 70% of a patient’s excess weight and that is a similar sort of figure for a gastric bypass, be it a mini gastric bypass or the Roux-en-Y gastric bypass."

Mr Chris Sutton, Consultant Specialist Bariatric Surgeon at Tonic Cosmetic Surgery


What Are The Risks?

Patients who undergo a gastric bypass are at risk of experiencing what is known as dumping syndrome. Characterised by sickness, nausea, diarrhoea and abdominal pain, the condition is brought on by a rapid change in the body’s sugar levels. Avoiding sugary foods and introducing high-fibre foods into your diet can lessen the chances of you experiencing dumping. Patients are also at risk of developing gallstones as a result of this surgery, and the surgical incisions can also become infected.

Two of the most serious complications are a pulmonary embolism (a blood clot in the lung), and issues pertaining to the new stomach pouch. There is the risk for example that the stomach pouch can become stretched, or there is a leak between the small intestine and the pouch. This can be serious and require immediate surgery to be repaired.


It is common for patients to feel tired and sore immediately following the surgery as the anaesthetic wears off. If you have undergone open surgery, you may have had a catheter fitted to pass urine into a bag, and you may also have tubes draining excess fluid from around the incision. You may also have a nasogastric tube, which is fitted into the nose and runs down to the stomach to ensure the stomach pouch remains empty. These will all normally be removed in the first couple of days following your surgery.

gastric bypass surgery

You may also have to wear special pumps to stimulate the blood flow in the legs to reduce the risk of clotting, in addition to compression stockings. In the days following your surgery, you may undergo an x-ray to ensure the sutures are healing and to check for any complications. Patients who don’t experience any abnormalities can return home two to five days after the surgery but will be unable to drive, so should arrange to be picked up when being discharged.


It is normal to experience pain bruising, and swelling around the incisions, for which you can take an over-the-counter pain medicine such as paracetamol or ibuprofen. You may also receive prescription painkillers if necessary. Patients recovering from a gastric bypass procedure should begin eating only liquids in the weeks immediately following the procedure. Puréed food can then be gradually introduced, and often your surgeon or dietician may suggest taking vitamin and mineral supplements as well.

Once you are able to resume eating solids, you may feel sick when eating, but this will pass as you adjust to smaller portions. Once you are able, adding in exercise to your daily routine will assist with weight loss. It can take anywhere between four to six weeks to make a full recovery, but this will vary between individuals. It is therefore important to follow your surgeon’s instructions, and report anything that feels out of the ordinary as soon as possible to prevent complications and get the all clear.

What Are The Alternatives To A Gastric Bypass Operation?

If you do not want to undergo gastric bypass, you could consider an alternative such as having a gastric band fitted, or a sleeve gastrectomy created. Speak to your surgeon to find out more about these alternatives.

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