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Gastric bypass weight loss surgery

We’re the UK’s most trusted weight loss & cosmetic surgery provider

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Gastric bypass surgery is a life-changing procedure that could help you lose weight, improve your health, and transform your entire lifestyle.

Gastric bypass may be suitable if you have a BMI (body mass index) of 40 or more, or a BMI of 35 or more if you also have an obesity-related condition such as Type 2 diabetes. New guidelines now suggest that surgery should be offered as a first line treatment if you have recently been diagnosed with Type 2 diabetes and your BMI is over 30. These parameters are guidelines, however, and every patient is different.

Losing weight on your own can be extremely difficult, and gastric bypass surgery is proven to be a highly effective weight loss procedure when combined with diet, exercise, and general lifestyle changes. A gastric bypass procedure could help you lose an average of 55-70% of excess weight after three years, according to the 2014 National Bariatric Surgery Registry Report.

Gastric bypass surgery involves removing or stapling some of the stomach and re-routing the small intestine. This assists weight loss by restricting food intake, reducing hunger and the absorption of calories and nutrients. A general anaesthetic is required for gastric bypass and depending on your medical condition and individual needs, the surgery can take 2 to 3 hours.

Our experienced patient advisors and highly qualified surgeons will explain the procedure and help you decide whether it’s the right route for you and your weight loss goals. Get in touch with us today to learn more about gastric bypass surgery.

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Gastric bypass results

See the weight loss success our patients have experienced through gastric bypass surgery:

Steven Pridmore

Gastric bypass

the hospital group gastric bypass

Olivia Coates

Gastric band conversion to gastric bypass

the hospital group gastric bypass

Why choose The Hospital Group for gastric bypass surgery?

The Hospital Group is the largest and most trusted UK provider of weight loss and cosmetic surgery group, with more than 25 years of experience.  We provide surgical excellence to our patients who put their trust in our care:

· Highly experience surgeons: when you’re putting your trust in a weight loss surgeon, only the most experienced will do. At The Hospital Group, we only select GMC-registered surgeons to work with us

· World-class facilities: we own state-of-the-art private hospital, Dolan Park in Worcestershire, and a network of 20 clinics across the UK that is constantly expanding

· Experienced team of dietitians: our team of dietitians have over 40 years combined experience of helping patients ensure they are meeting all their nutritional requirements following bariatric surgery, and so achieving their goals safely and healthily

· Dedicated weight loss support team: whether you need to book an appointment with a nurse, our dietitians, your surgeon or just have a general question following your surgery, we are here to support you every step of your journey

· Full weight loss journey aftercare:  you can choose between 1 to up to 6 years of aftercare as part of your original surgery package but our aftercare goes beyond and with us you will always have the option for continuous, even life time support 

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What is the difference between a gastric band and a gastric bypass?


Both the gastric band and a gastric bypass are forms of bariatric surgery, which can help you lose weight over time. However, they are different types of surgery that can have different results.

· Gastric bands: Explained

A gastric band is a hollow tyre-like silicone device, which is wrapped around the very top of the stomach.  Here, it stimulates nerve endings in the stomach wall helping you to feel less hungry.  The band also slows you down when eating, requiring you to take smaller mouthfuls and chew more thoroughly.  This helps you to realise more easily when you have had enough to eat.

Gastric bands are reversible, and do not remove any part of your stomach. You also will be able to absorb vitamins and minerals naturally after a year and won’t necessarily need to follow a supplement routine for life.  The only supplement needed then is an off-the-shelf multivitamin and mineral.  This just helps to off-set the fact that you will only be eating small portions.

Some drawbacks of the gastric band are that the balloon can move and require additional surgery. Weight loss results can also vary more than other forms of bariatric surgery.


· Gastric bypass: Explained

Gastric bypass surgery involves separation of the top of your stomach from the main body of your stomach by stapling, and re-routing of your small intestine so that food will pass directly from the new smaller stomach into the small intestine.

They are one of the most successful forms of bariatric surgery for long-term weight loss, as the size of the stomach means patients can only eat smaller meals. The bypass itself causes metabolic and hormonal changes, which result in increased satisfaction and reduced feeling of hunger. There is some evidence to suggest that you will also not absorb as many calories from food.

A gastric bypass is a permanent form of weight loss surgery, and therefore is only offered to those with a high BMI. Patients are also required to make more major lifestyle changes than the gastric band, and these changes must be followed due to the permanence of the surgery – it cannot be reversed.

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What happens during a gastric bypass procedure?

There are two main types of gastric bypass surgery, though both essentially work in the same way. 

Both involve the creation of a small stomach pouch – this reduces your portion sizes.  Both also involve the re-routing of the small intestine so that food does not pass through the main body of the stomach or the first part of the small intestine.  Instead, food passes straight into the lower part of your small intestine – this results in metabolic and hormonal changes, which help you to feel more satisfied on smaller portions and overall less hungry.  You will also absorb fewer calories, protein, fat, vitamins and minerals from the food you eat (supplements are needed to help counteract this).

1. Roux-en-Y gastric bypass (RYGB)

This is the main type of gastric bypass and has long been considered the “gold standard” of weight loss surgery.  The first one was performed in 1967.  During this type of bypass, two joins are made – one between the stomach & the small intestine and a second between the upper and lower small intestine.  This creates the characteristic “Y” shape.

2. One anastomosis gastric bypass (OAGB)

Mini” gastric bypass or “omega loop” gastric bypass which is a newer procedure, first performed in 2001.  In this operation, only one join is made - the small intestine is attached directly to the pouch creating a loop shape instead of a “Y”.

What gastric bypass packages do we offer?

As weight loss surgery is a long-term journey which requires a number of lifestyle changes, rather than simply a short-term route to losing weight, it’s important to think about aftercare so you are fully supported and best placed to achieve your goals. Whether you opt for prime, plus or premium, rest assured with us you will be supported through every stage of your journey. 


All our gastric bypass packages include: 

  • · Your hospital, anaesthetist and surgeon fees
  • · Appointments with our expert dietitians
  • · Regular support from our specialist nurses
  • · Surgical cover for the length of your package
  • · 24-hour emergency support line
  • · Private transport option to and from surgery

Prime, plus and premium packages offer varying levels of care and support to ensure you’re best positioned to achieve your weight loss goals. Our Patient Advisor will help you make the right choice. Here is what else comes in each of our bypass packages:

gastric bypass prime package

· 13 dietitian appointments

· 1-year surgical cover

Gastric bypass plus package

· 19 dietitian appointments

· 2-year surgical cover

Gastric bypass premium

· 28 dietitian appointments

· 6-year surgical cover

Is gastric bypass surgery painful?

As with any abdominal surgery, you may find you need pain relief following surgery. The recovering process typically takes between 2 to 4 weeks on average, and during this time you may need access to pain relief.

Your abdomen in general may feel sore, and the site of your wounds may hurt. However, any severe pain should be reported to your weight loss care team.

Gastric bypass surgery frequently asked questions

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When you’re deciding whether to have surgery, it’s reassuring to have all the facts. You’ll be able to ask any questions at your consultation, but here are some that our patients most frequently ask.

Gastric bypass FAQs

Gastric surgery is a proven method of weight loss and is ideal when you have a lot of weight to lose and have tried many conventional methods of weight loss without long term success. The Hospital Group will not only provide your surgery but also a team of specialist dietitians, nurses and weight lot support team to help you get the best possible results on your weight loss journey.

No, this type of weight loss surgery is permanent. If you are looking for something less permanent then you could consider a gastric band instead.

The WHO (World Health Organisation) believes that being overweight/obese is major risk factor for diabetes. The unique changes in gut hormones that happen after a gastric bypass are also thought to improve diabetic control, independently of weight loss. While we cannot guarantee a change in your personal management of diabetes, many of our patients have been able to reduce their diabetic medications and improve their diabetes overall following gastric bypass surgery. While every patient is different, new guidelines say gastric bypass could be an effective first-line treatment for this condition.

It’s possible to have a revision to your gastric bypass, however this does have increased risks of complications. For this reason, a second gastric bypass generally won’t be offered if you’ve regained weight and not followed the changes you needed to make to your diet and lifestyle.

This depends on the patient and the surgeon but usually gastric bypass operations take between 90 minutes and two hours if performed by keyhole surgery (almost always the case). If you are having your gastric band removed at the same time, the operation will usually take longer, but you can discuss this with your surgeon.

This again depends on the patient and the surgeon, but usually you’ll need to stay in hospital for 2-3 nights, although sometimes you may be able to go home after one night.

For the seriously obese, the benefits of the gastric bypass procedure tend to outweigh the risks. The benefits generally include: Improvements in risk factors for heart disease and cancer Up to 85% of patients with hypertension will be off medication (source: National Bariatric Surgery Registry Report 2014) Cholesterol levels will fall 80% of Type 2 diabetics will be off medication after 3 years (source: National Bariatric Surgery Registry Report 2014) Improvements in a range of conditions, including sleep apnoea, asthma, joint pain, arthritis, reflux, fatigue and shortness of breath Patients report less depression, improved self-esteem and confidence, along with an increased sense of wellbeing.

After 2-3 months, most patients are back on a varied diet of solid food. However, some patients may struggle with certain textures of food such as bread or red meat. In addition, a phenomenon known as Dumping Syndrome can occur if too much sugar is consumed – this results in symptoms such as dizziness, sweating, palpitations and bloating. Often patients say that these symptoms help to discourage them from eating too much sugar, which can then enhance weight loss.

As with any surgery, there can be operative and long-term complications and risks associated with gastric bypass, including: Bleeding Complications due to anaesthesia and medications Infections Blood clots on the lung Deep vein thrombosis Wound breakdown Leaks from the staple line Injury to the spleen Marginal ulcers.

We have an expert team of dietitians, who will be able to help you make sure you’re getting all the nutrition you need. Generally, you’ll have to follow a more nutritious diet since your portions will be smaller and fewer nutrients will be absorbed. It is also important you are managing a good protein intake, so our dietitians will advise you on this. Also, because you won’t be able to absorb as many vitamins and minerals, you’ll have to take supplements for life and have regular blood tests to check for any nutritional deficiencies.  Here at The Hospital Group, we offer a wide range of weight loss supplements to help you along the way.

Gastric bypass surgery reduces the size of your stomach as well as bypassing part of the small intestine. This means that you will only be able to manage smaller portions of food, your body will absorb fewer calories, and changes in your gut hormones will lead to a reduced feeling of hunger. You should also feel satisfied for longer on your smaller portions. As with any weight loss, a healthy diet and regular exercise are needed alongside your surgery for the best results. You will have to make a few lifestyle changes.

The recovery time for gastric bypass surgery varies from person to person. Your surgeon and bariatric team will advise on this within your personalised care plan. After your surgery, you’ll have to stay in hospital for two to four nights.  We then advise nothing too strenuous for at least six weeks after your surgery.

The cost of a gastric bypass varies but you can use our price check for a guide. We also have finance options available to help you spread the cost of your treatment over 24, 36, 48 or 60 months. For example, if you wanted to pay for a £9,145 procedure over 60 months, you could put an initial deposit of £500 down and then, based on 12.9% APR, your monthly instalments would be £193.18 per month and you would eventually pay £12,090.80 in total.

You can also choose our 0% finance option which allows to spread the costs of the surgery over a 6, 10 or 12-month period without incurring any interest.

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What are the risks of gastric bypass surgery?

While the risks of gastric bypass surgery today are small, there are some risks that should be considered before undergoing the surgery. Some of these risks take place during and directly after the surgery, while others are long-term.

The immediate risks of gastric bypass surgery include:

  • · Bleeding
  • · Anaesthesia complications
  • · Infection
  • · Blood clots on the lungs
  • · Deep vein thrombosis
  • · Wound breakdown
  • · Leaks from the staple line
  • · Spleen injury
  • · Ulcers

These are all rare, and your weight loss care team will discuss them in detail with you when planning surgery.

The long-term complications of gastric bypass surgery are usually a result of not following the necessary lifestyle changes that will ensure you don’t become vitamin or mineral deficient. Those who have had a gastric bypass may need to take nutritional supplements for life, which can include specific doses of multivitamins and minerals, iron, vitamin B12, calcium and vitamin D.

Some patients who have undergone gastric bypass surgery also report a side effect known as ‘dumping’. This refers to cramping. light-headedness and lethargy that can happen after eating or drinking anything high in carbohydrate (especially sugar).

However, following a dietary plan will help to reduce the risk of this and other possible side effects.

More details on gastric bypass surgery

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At The Hospital Group, we’re here to look after you. As UK market leaders in weight loss management, we offer advice you can trust, treatment based on your individual needs, and support throughout your journey with us. Here’s a step-by-step guide to what you can expect.

Gastric bypass details

We want you to make a fully informed decision before you go ahead with surgery, so we offer a private consultation at your local clinic free of charge. At your consultation, you’ll meet with a bariatric surgeon to discuss the weight loss options available and whether gastric bypass surgery is the most suitable procedure for your needs. You’ll be able to ask questions about all aspects of the surgery, from aftercare and dietary changes to the results you can expect. You’ll also meet your patient care coordinator, who will be with you every step of the journey. They will give you a personal quotation of costs and information about finance options, the expected timescale, our surgical facilities and door-to-door transport services.

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At your consultation, you can book your surgery if you feel ready, but there’s no obligation to go ahead.Bariatric surgery is a big step and you may want to take time to do more research and think about your decision. We’ll give you a patient information booklet, which provides comprehensive information on your weight loss procedure, aftercare and dietary guidelines. This is an important resource and we require patients to read the detailed information it contains. You’ll also find lots of helpful information here on our website – you can read about our surgeons’ qualifications, THG’s weight loss management expertise and inspiring stories from some of our patients. Our patient care coordinators are available to discuss any concerns you may have. And when you feel ready, they can book you in for your procedure. We also have a 14-day ‘cooling off’ period in place, which means that if you change your mind about the procedure after booking within that period, you will not be charged.

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On the day of your surgery, your medical team will make your experience as comfortable as possible and you’ll meet your surgeon again before the procedure. Gastric bypass surgery is carried out under general anaesthetic. There are several varieties of bypass, but all involve dividing the stomach to create a small stomach pouch and then attaching a section of the small intestine to the pouch, therefore bypassing part of the small intestine. The smaller stomach pouch restricts the amount of food you can eat, and is designed to make you feel full after smaller meals. It also aims to drop appetite hormone levels to reduce your appetite. Bypassing part of the small intestine reduces the amount of calories you absorb from food, as well as vitamins and minerals and so supplements are required for life. Gastric bypass surgery is non-reversible.

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We’ll be here throughout the recovery process to help you recuperate quickly. For gastric bypass surgery you’ll need to stay in the hospital where your surgery has taken place for 2-4 nights, depending on your procedure. Each patient is given a personalised care plan, developed on the advice of their surgeon. All THG hospitals are equipped to the highest standards of clinical care and patient comfort.

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When you have a gastric bypass, the surgery is only the start of your journey. At THG, we offer a full package of aftercare support to help you achieve your weight loss goals. You’ll benefit from the following aftercare for 2 years: Access to a dedicated weight loss support team who can help with booking appointments, emotional support, practical ideas and solutions Specialist support from a bariatric surgeon, dietitians and nurses Surgical cover for 6 months 24-hour emergency telephone helpline.

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