Gastric bypass surgery

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

The procedure involves reducing your stomach size, from 1500ml to around 30ml, and then connecting it to the lower part of your small intestine.

This restricts the amount of food you can eat and the number 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, risk of stroke, heart disease, gastroesophageal reflux, sleep apnoea and polycystic ovaries
• 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 and anaesthetic

Your BMI can be calculated by using this equation: Weight (kg) ÷ Height (m)²

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.

Gastric bypass surgery is not recommended for children and young people, and you may have to pass a psychological assessment first.

Alternatives to gastric bypass surgery include:

• Gastric band surgery
• Intra-gastric balloon
• Biliopancreatic diversion

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’

Who will be involved?

As well as your bariatric surgeon, you'll also be seen by a:

• Dietitian – to talk to you about your diet
• Clinical Nurse Specialist
• Anaesthetist – to administer anaesthetic during the operation

You may also be seen by a psychologist to talk to you about the emotional aspects of a gastric bypass and understand how we can support you through this process.

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 lose weight and follow a calorie-controlled diet, low in carbohydrates and fats, to reduce the size of your liver. This is important for keyhole bariatric surgery as your liver will have to be moved out of the way so your surgeon can access the stomach. If your liver is smaller, the operation will be easier and safer. It’s advised that you stop smoking three months before your surgery.

You’ll be admitted to the hospital either the day before or on the day of your procedure. You shouldn’t eat for several hours before your gastric bypass, but you can continue to drink clear liquids until two hours before the operation. Should you need to stop any medication in preparation for your bypass surgery, your doctor will tell you. You’ll also have plenty of time to ask any questions and discuss your concerns before your surgery.

You may find it helpful to organise for someone to drive you home after your surgery and stay with you for a couple of days to help out while you recover.

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
• Inflate your abdomen with carbon dioxide gas
• 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. After your surgery, you’ll be given compression stockings or blood-thinning medication to reduce your risk of blood clots which can lead to complications such as deep vein thrombosis (DVT) and pulmonary embolisms. You’ll stay until you have completed your X-ray normal swallow test and started your diet plan, this can be a further one to two days.

You may find it helpful to have someone drive you home and stay with you for a couple of days after your operation, while you recover.

Recovery time

You should be back to your normal activities by six weeks after following a controlled diet 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. After three to six months you should be experiencing less of these symptoms and you’ll have lost most of your weight around two years after your surgery.

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
• Discharge medication – which can include vitamin D, calcium, multivitamin A-Z with iron, vitamin B12, Lansoprazole
• Follow-up appointments

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 also won't be able to eat until you’ve had an X-ray and swallow test. After this, you’ll be able to eat soft foods at first and your dietitian will give you a comprehensive diet plan for the weeks after your surgery.

You’ll need to wear compression stockings for the two weeks after your surgery to prevent blood clot formation. You can shower but must not bathe for a week, and you must ensure that all dressings are kept clean and dry. 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’ll also have blood tests at regular intervals for the first two years after your surgery.

You can expect to return to work between two to four weeks after your surgery, though this depends on how strenuous your job is – you’ll have to request a fit note from your ward doctor should you need one. You can usually drive within two weeks of your surgery, but you should check your policy first.

You should keep active after your operation to reduce the risk of blood clots forming, however, you should try to avoid any abdominal or heavy exercises for at least six weeks.

As you start to lose weight after your bypass surgery, your body will need more protein to maintain your muscle mass and have a healthy metabolism. You’ll need to increase the amount of protein in your diet otherwise your body will start to rely on the protein from your muscles which will weaken them.

Avoid drinking at the same time as eating to prevent vomiting and dumping syndrome. This is an uncomfortable set of symptoms caused by the food in your stomach being too sugary, or quickly washed into the small intestine through the join. Ensure that you're drinking plenty of water throughout the day to prevent constipation.

If you’re planning to travel by plane within a few months of surgery, you should speak to your doctor first. Some complications may occur including deep vein thrombosis (DVT).

You can continue to have sex when you’re ready but 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.

Side effects

You may find that you start to lose some hair, or it becomes thinner after your weight loss. Although this can be distressing, it is only temporary and will usually improve after a few months. You may also find that your skin becomes very dry after your gastric bypass surgery, you can improve this by drinking plenty of fluids, taking your multivitamins and applying a good moisturising cream regularly.

As your body reacts to rapid weight loss in the first three to six months, you can also experience body aches, tiredness, flu-like symptoms, feeling cold and mood changes.

Results

The amount of weight you lose depends on your change in lifestyle habits, though you can expect to lose up to 90% of your excess weight within one year of surgery. As well as your weight loss, you may find that your gastric bypass surgery will improve other conditions related to being overweight including heart disease, high blood pressure and joint pain.

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.

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
• Changes in mental wellbeing such as depression and maladaptive eating
• Regaining weight and the recurrence of obesity-related illnesses
• Breathing problems
• Stricture – where the connection between the stomach and intestine narrows
• Deep vein thrombosis (DVT) and pulmonary embolism

Although rare, anaesthetic complications can include:

• Chest infections
• An unexpected reaction to the anaesthetic

You should call the hospital you had your procedure at or seek medical advice if you experience any of the following after surgery:

• Stomach pains that don’t go away or get progressively worse
• Fast heartbeat
• High temperature
• Chest pains or shortness of breath
• Vomiting or vomiting blood
• Difficulties in swallowing
• Dark or sticky faeces
• Wound infection – pain, redness, swelling or pus

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