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Weight loss surgery, also called bariatric surgery, has been found to be an effective treatment in some obese people. However, it is only available on the NHS if your obesity is affecting your health, and other treatment options have been tried and have not worked.

You will probably only be able to receive weight loss surgery on the NHS if:

  • you have a BMI of 40 or more, or a BMI of between 35-40 and also have a serious health condition that could be improved if you lose weight, such as type 2 diabetes or high blood pressure,
  • you have tried all the appropriate non-surgical methods, such as diet and exercise, but have failed to achieve or maintain a beneficial level of weight loss for at least six months,
  • you agree to commit to the need for long-term follow-up treatment after surgery at a specialised obesity service, and
  • you are fit and healthy enough to withstand the anaesthetic (painkilling medication) and surgery.

There may be slightly different criteria at your local primary care trust (PCT) that could affect your access to surgery. In most cases, you need to have been referred for surgery by a specialist obesity management service (not just your GP). 

How surgery is performed

Weight loss surgery is usually performed under general anaesthetic (where you are unconscious and cannot feel anything). In most cases you will need to stay in hospital for between 1-4 days. This may be longer if your procedure is particularly complex.

Surgery may be performed as:

  • open surgery - when an incision (cut) is made into your abdomen, or
  • laparoscopic surgery - when a small hole is made in your abdomen and surgery is performed through this using special instruments.

In general, laparoscopic surgery may be safer as it is less invasive (makes a smaller incision) and the recovery time is shorter. However, the technique is more challenging for the surgeon, and it may not always be possible.
See the complications section below for more information on the possible complications of surgery.

Types of weight loss surgery

Weight loss surgery aims to:

  • restrict the amount you can eat - for example by reducing the size of you stomach,
  • restricting the amount of calories that are absorbed from what you have eaten - for example by changing how you digest food, or
  • a combination of both of these.

There are many different types of weight loss surgery. The type of surgery that you have will be decided jointly by you and your surgeon. It will depend on your BMI and general health, as well as what equipment and facilities are available.

Possibilities include:

  • gastric band surgery,
  • gastric bypass surgery,
  • bilopancreatic diversion,
  • sleeve gastrectomy, and
  • intra-gastric balloon.

These are described in more detail below. For more information on these and other procedures, see the British Obesity Surgery Patient Association website.

Gastric band surgery

Gastric band surgery, or gastric banding, is a surgical procedure that involves fitting a band around the upper part of your stomach. Once the gastric band is in place, it effectively divides your stomach in two, creating a smaller pouch at the top.

Having a small stomach pouch will mean you need to eat less to feel full. The food then slowly passes down into the rest of the stomach and is digested in the normal manner.

A gastric band is designed to remain permanently in place. The newer kinds of gastric bands can also be adjusted without the need for more surgery. Adjusting the band changes the size of the stomach pouch, which will affect how much you can eat.

Gastric bypass

A gastric bypass is a similar procedure to a gastric band, as small stomach pouch is created from the upper part of your stomach. However the pouch is not connected to the rest of the stomach. Instead, it is surgically re-routed to the small intestine (the part of your digestive system where nutrients are absorbed into you body), bypassing the rest of your stomach.

The gastric bypass helps you eat less because the small pouch means you feel full sooner. You also lose weight because bypassing the rest of the stomach means that you are absorbing less calories from the food you do eat.

Bilopancreatic diversion

This procedure is a combination of those above. It involves removing most of the stomach to leave a small stomach pouch. This is then reconnected to the final section of the small intestine, bypassing most of it. The fluids that are used to digest food are also diverted. This means that food remains undigested, and less calories are absorbed.

This type of surgery is very technical and only partly reversible. The procedure can be adapted to give slightly different results, for example by changing how much food is absorbed during digestion. 

Sleeve gastrectomy

This type of surgery may be considered if you are at high risk from other types of operations, for example because you are very obese. This procedure divides your stomach vertically in a line, reducing the size of your stomach by about 75%. The way you digest food is unaffected. The procedure cannot be reversed

As your stomach is smaller, you need to eat less to feel full, and you lose weight. After 6-12 months, your stomach may start to expand, which could mean that you start eating more. At this point, a second type of surgery may be considered, if it is now safe to do so.

Intra-gastric balloon

An intra-gastric balloon is a soft silicone balloon that is surgically implanted in your stomach. The balloon is filled with air or saline solution (salt water), and so takes up some of the space in your stomach. This means you do not need to eat as much before you feel full.

This procedure is only temporary, and the balloon is usually removed after six months. This procedure is useful if you do not meet the criteria for the other types of surgery, for example because you are too obese.

An intra-gastric balloon procedure can usually be done without making an incision in your abdomen. Instead, the balloon can be passed through your mouth and down into your stomach using an endoscope (a thin, flexible tube that has a light and a camera on one end). For more information, see therapeutic gastroscopy.

Prices for private surgery

Some kinds of surgery may be available privately. Prices can vary, depending on the clinic and your individual circumstances, but as a general guide:

  • prices for gastric banding are in the region of £5,000 to £8,000,
  • prices for gastric bypass surgery are in the region of £9,500 to £15,000, and
  • prices for an intra-gastric balloon are in the region of £3,500.

Make sure that the price you are quoted includes everything you will need in your treatment, including any scans and tests before surgery, and any follow-up appointments after surgery. You should also make sure that you use a properly qualified and experienced surgeon.

Children and surgery

Weight loss surgery is not usually recommended for children or young people. In exceptional circumstances, and only if the child is almost physically mature (completed puberty), surgery may be considered.

Complications from weight loss surgery

Whilst weight loss surgery is considered an effective way to treat obesity, it does carry some risks. In general, the risk of death following weight loss surgery is thought to be around one in 360. Other possible complications include:

  • infection at the site of the wound,
  • vomiting - from over-eating as you get used to your stomach being a smaller size, 
  • failure to lose weight,
  • acid reflux - when stomach acid leaks back up into the oesophagus (the tube that runs from your throat to your stomach),
  • leaks from where the stomach has been closed or where the stomach has been re-attached to the intestine (part of the digestive system),
  • the band used for gastric band surgery could slip out of position,
  • loose or foul smelling stools,
  • bloating, and
  • ulcers (open sores) forming in the stomach.

Surgery that restricts the absorption of calories and nutrients from the food you eat, such as bilopancreatic diversion, can also cause other complications. For example, the lack of nutrients can cause:

  • hair loss (alopecia),
  • a lack of energy (fatigue), and
  • protein malnutrition (not having enough protein in your diet).  

Complications are more likely in longer or more complex surgical procedures. Some of these will require further surgery to correct them, for example of there is a leak in your stomach, or if your gastric band has slipped out of position.

Before your operation, ask your surgeon to explain the possible risks to you, and how likely they are to affect you.    

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