Gastric bypass surgery

We offer the latest surgical techniques to help you lose weight when diet and exercise haven't worked and your health is at risk because of severe obesity.

Sometimes also called

  • Roux-en-Y bypass

At a glance

  • Typical hospital stay
    2-5 nights

  • Procedure duration
    1-3 hours

  • Type of anaesthetic

  • Available to self-pay?

  • Covered by health insurance?
    Some insurers, by exception

Why Spire?

  • Fast access to treatment when you need it
  • Consultants who are experts in their field
  • Flexible payment options to help you spread the cost
  • 98% of our patients are likely to recommend us to their family and friends

What is gastric bypass surgery?

A gastric bypass, also known as a Roux-en-Y, is an operation your doctor may suggest if your health is at risk due to severe obesity.

The procedure involves reducing your stomach size and connecting it to the lower part of your small intestine.

This restricts the amount of food you can eat and the amount of calories you’re able to absorb through your small intestines. It also causes hormonal changes that deter you from eating unhealthy foods.

The benefits of gastric bypass surgery are:

  • Weight loss – on average people lose between 66% and 75% of excess weight in the two years after gastric bypass surgery
  • Improvements in any weight-related conditions you may have, such as type 2 diabetes, high blood pressure, high cholesterol and heart disease
  • You're more able to do physical activity which can lead to increased energy, fitness, strength, stamina, bone density, improved mood and self-confidence

Your doctor may recommend gastric bypass surgery if:

  • You have a BMI of 40 or higher - this is known as ‘morbid obesity’
  • You have a BMI between 35 and 40 together with a serious condition that could be improved with weight loss
  • You’ve tried to lose weight through diet and lifestyle
  • You’re willing to have long-term follow-up appointments and adopt a healthy diet and lifestyle
  • You’re medically fit for surgery

Your doctor may recommend gastric sleeve surgery first. This is an operation to reduce the size of your stomach without changing how your digestion works.

Find your nearest Spire hospital

Almost all our hospitals offer gastric bypass surgery and have teams of bariatric (weight loss) consultants and surgeons who specialise in this procedure.

Spire Nottingham Hospital

How gastric bypass surgery works

Your surgeon uses surgical staples to make a small pouch at the top of your stomach and connects it to the lower part of your small intestine. This means the food that you eat will bypass the rest of your stomach and the upper part of your small intestine, going straight into your lower small intestine.

This helps you lose weight in three ways:

  • Restriction - you won’t be able to eat as much as before because there won’t be room in your new, smaller stomach pouch
  • Malabsorption - you’ll absorb fewer calories because your food will come into contact with less of your small intestine
  • Deterrent – you won’t feel like eating a lot of sugar because if you do, your body will produce too much insulin, making you feel light-headed and sick. This is called ‘dumping syndrome’

Your operation: what to expect

Before surgery

You’ll be assessed to check that you’re fit for the operation. This may include blood tests, X-rays and scans, as well as an explanation of the surgery and long-term outlook.

You may need to follow a calorie-controlled diet to reduce the size of your liver. This will make the operation easier and safer.

During the surgery

A gastric bypass is a major operation so it’s carried out under a general anaesthetic, meaning you’ll be asleep.

It’s usually done by laparoscopic (keyhole) surgery, though this method isn’t suitable for everyone. Keyhole surgery has a much faster recovery time than traditional open surgery.

During the operation, your surgeon will:

  • Make small incisions (cuts) in your abdomen and pass through a tiny camera and instruments
  • Use surgical staples to make a pouch, about the size of a walnut, at the top of your stomach
  • Cut your small intestine and attach the lower part of it directly on to your new pouch
  • Join the remainder of your stomach and upper small intestine to the lower part – so digestive juices from your stomach can drain out
  • Close your incisions

If your surgeon thinks keyhole surgery isn’t suitable for you, they may suggest open surgery, which involves making one single, much larger cut.

How long does a gastric bypass operation take?

Between one and three hours.

Pain after gastric bypass surgery

It’s normal to feel some pain and discomfort after gastric bypass surgery, though it’s different for everyone. You’ll be given pain relief to help you.

Your hospital stay

You’ll usually be in hospital between two and five nights.

Q & A

Simon Monkhouse, Consultant Upper GI and Bariatric Surgeon

Talking about gastric bypass surgery

Your recovery: what to expect

Recovery time

You should be back to your normal activities by six weeks but may experience changes as your body reacts to rapid weight loss in the first few months. This includes symptoms such as aches, tiredness, dry skin, feeling cold, thinning hair and mood changes.

Aftercare and ongoing treatment

Your recovery care will include:

  • Pain relief
  • A review of any medicines you’re taking for weight-related conditions, such as diabetes or high blood pressure
  • A carefully controlled diet plan for the first four to six weeks, moving from liquids to pureed, soft then solid foods, plus advice on eating and portion sizes
  • An exercise plan to help speed your weight loss and improve your fitness
  • Blood tests to check if you need extra vitamin and mineral supplements

Your lifestyle after treatment

The surgery won’t stop you craving or eating unhealthy food, so you must be willing to make long-term lifestyle changes.

You’ll need to attend follow-up appointments for the rest of your life. Eventually, these may just be annual checks to make sure your bypass is working properly.

You should avoid becoming pregnant during the first 12 to 18 months after surgery. Your nutritional levels are likely to be low during this time, which could harm your baby.

Risks and complications

Most people have gastric bypass surgery without complications, but all surgery carries some risks. Your consultant will explain them to you before you go ahead.

Although rare, gastric bypass complications can include:

  • Blood clots
  • Infection
  • Food leaking from the join between your stomach and small intestine, or the gut becoming blocked or narrowed
  • Nutritional deficiencies
  • Gallstones
  • Folds of skin due to rapid weight loss – further surgery can remove them

At Spire hospitals, your safety is our top priority. We have high standards of quality control, equipment and cleanliness and an ongoing system of review and training for our medical teams.

Treatment and recovery timeline

Although everyone’s different, here’s a typical recovery timeline for gastric bypass surgery:

View interactive timeline View full timeline

2-5 days

Able to leave hospital

4-6 weeks

Follow a controlled, monitored diet

4-6 weeks

Back to most activities and some weight loss

3-6 months

Less symptoms of rapid weight loss

2 years

Most weight loss will have happened

  • 2-5 days

    Able to leave hospital

  • 4-6 weeks

    Follow a controlled, monitored diet

  • 4-6 weeks

    Back to most activities and some weight loss

  • 3-6 months

    Less symptoms of rapid weight loss

  • 2 years

    Most weight loss will have happened

The treatment described on this page may be adapted to meet your individual needs, so it's important to follow your healthcare professional's advice and raise any questions that you may have with them.

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