Gastric bypass surgery
Published by Bupa’s Health Information Team, December 2010.
This factsheet is for people who are having gastric bypass surgery, or who would like information about it.
Gastric bypass is a type of weight loss surgery. It works by making the stomach smaller and the digestive system shorter.
You will meet the surgeon carrying out your procedure to discuss your care. It may differ from what is described here as it will be designed to meet your individual needs.
About gastric bypass surgery What are the alternatives? Preparing for a gastric bypass operation What happens during a gastric bypass operation? What to expect afterwards Recovering from gastric bypass surgery What are the risks? About gastric bypass surgery A gastric bypass is an operation to make your stomach smaller and to shorten the length of small intestine that the food then passes through. This allows the food you eat to bypass most of your stomach and part of your small intestine. This means that you eat less and that some of the food you eat won’t be fully digested. It can help you lose weight if you’re very overweight (morbidly obese).
Gastric bypass surgery is sometimes called a Roux-en-Y gastric bypass (named after a surgeon called Roux). This is the most common gastric bypass operation done in the United Kingdom.
Your doctor will usually suggest you may be suitable for a gastric bypass operation only if you have tried other methods of weight loss, such as diet, exercise and medicines, and these haven’t worked. This type of operation will only be offered to you if:
you’re very overweight with a body mass index (BMI) of more than 40 you have a BMI of between 35 and 40 and have a medical condition, such as diabetes or high blood pressure, that might improve if you lose weight What are the alternatives? There are other types of surgery available that can help you to lose excess weight. Some of these involve creating a smaller stomach by inserting an adjustable band.
Your surgeon will talk to you about the options available.
Preparing for a gastric bypass operation When you meet your surgeon, this is your opportunity to understand what will happen, and gives you the opportunity to discuss and ask questions about the risks, benefits and your alternatives. Your surgeon will tell you about the options available to you and the pros and cons of each.
Your surgeon will explain how to prepare for your operation. For example, if you smoke you will be asked to stop, as smoking increases your risk of getting a wound infection, a chest infection or a blood clot and slows your recovery. This is particularly important before a gastric band operation as excess weight also increases your risk of a complication. You may be given a pre-operative diet to follow which is aimed at shrinking your liver, which gives your surgeon easier access to your stomach. You may be given printed advice in the form of a booklet.
A gastric bypass operation is usually done under general anaesthesia. This means you will be asleep during the operation. You will usually have to stay in hospital for between two and five days after your operation.
You will be asked to follow fasting instructions. This means not eating or drinking, typically for about six hours beforehand. However, it’s important to follow your surgeon’s advice.
At the hospital your nurse may check your heart rate and blood pressure, and test your urine.
Your surgeon will discuss with you what will happen before, during and after your procedure, and any pain you might have. This will help you to be informed, so you can give your consent for the procedure to go ahead, which you will be asked to do by signing a consent form, which your surgeon also signs.
You may be asked to wear compression stockings and be given an injection of an anti-clotting medicine called heparin to help prevent blood clots forming in the veins in your legs.
What happens during a gastric bypass operation? A gastric bypass operation usually takes between one and three hours.
A gastric bypass operation is usually done using keyhole (laparoscopic) surgery. It can also be done through a single, longer incision. During keyhole surgery small cuts are made in your abdomen (tummy) rather than one large cut. During a keyhole operation your surgeon uses small instruments, guided by a special telescope with a camera, to perform the operation.
However, if you’re very overweight or have had surgery to your abdomen before, then your surgeon may recommend having an open operation, which is performed through a single larger incision.
Using surgical staples your surgeon will make a pouch at the top of your stomach, separating it from the lower part of your stomach. A new opening from this pouch is made. This is connected to a section of your small intestine so that food can bypass your old stomach and the first part of your intestine. Sometimes a drain is inserted to stop fluid from collecting inside your abdomen.
Afterwards, the cuts are closed with stitches or small metal clips. A dressing is placed over the wounds.
What to expect afterwards You will need to rest until the effects of the anaesthetic have passed. You may need pain relief to help with any discomfort as the anaesthetic wears off.
If you had open surgery, you may have a catheter to drain urine from your bladder into a bag. You may also have fine tubes coming from the wound which drain fluid into another bag and are usually removed after a day or two.
On the first day, you may have to wear special stockings on your lower legs, which are attached to an intermittent compression pump. The pump inflates the stockings and encourages healthy blood flow in your legs and helps to prevent deep vein thrombosis (DVT).
You may also need to wear compression stockings to help maintain your circulation. You will be encouraged to get out of bed and move around as this helps prevent chest infections and blood clots in your legs. You may have a nasogastric tube fitted (a tube inserted into your nose that goes down to your stomach) to keep your stomach pouch empty. This is usually removed after one or two days.
You will have a drip inserted into a vein in your hand or arm to give you fluids. If you feel well enough, you can start to drink small amounts of water soon after your operation.
Two to four days after your operation you may have an X-ray to check there are no leaks. You may be asked to swallow a fluid (barium) that shows up on X-ray images. If the X-ray shows that the operation has been successful, you will be able to start drinking freely, including soups and fruit juice.
You will usually be able to go home two to five days after your operation. You will need to arrange for someone to drive you home.
Your surgeon may use dissolvable stitches. The length of time your dissolvable stitches will take to disappear depends on what type you have. However, for this procedure they should usually disappear in seven to 10 days. If you have non-dissolvable stitches or clips you will need to have them taken out. Your surgeon will tell you when and where to have them removed.
Your nurse will give you advice about caring for your healing wounds before you go home and give you a date for a follow-up appointment.
Recovering from gastric bypass surgery If you need pain relief, you can take over-the-counter painkillers such as paracetamol or ibuprofen. Always read the patient information that comes with your medicine and if you have any questions, ask your pharmacist for advice.
You will need to make changes to the foods you eat after your operation and you will only be able to eat small amounts at each meal. You will be given specific dietary advice. Initially your diet needs to be very soft and pureed; your dietitian or surgeon will explain how to reintroduce solids into your diet. You may also be asked to take vitamin and mineral supplements.
You will be asked to make other changes to your lifestyle, such as becoming more active. These changes will help you to get the most from your gastric bypass operation and will help you to lose weight and keep it off. Your dietician and surgeon will give you more advice about the foods you can eat and what other changes you need to make.
You may need to have regular blood tests after your operation. These are to check that you’re getting all of the vitamins, minerals and nutrients you need to stay healthy.
It usually takes between four and six weeks to make a full recovery from a gastric bypass operation. However this varies between individuals, so it’s important to follow your surgeon’s advice.
What are the risks? As with every procedure, there are some risks associated with gastric bypass surgery. We have not included the chance of these happening as they are specific to you and differ for every person. Ask your surgeon to explain how these risks apply to you.
Side-effectsSide-effects are the unwanted but mostly temporary effects you may get after having the procedure. You’re likely to have some bruising, pain and swelling of the skin around your wounds.
You may feel or be sick after eating, because the amount you’re able to eat is a lot less than before the operation. This will get better as you change your eating habits.
If you eat too many sugary foods, you can get an unpleasant sensation called dumping. This is when the food moves too quickly through your digestive system and causes your blood sugar or blood pressure to fall. This is very rare if you follow your diet closely. It may make you feel sick or faint, or give you abdominal pain and diarrhoea. Eating small meals and eating little or no sugary food will help to ease these symptoms. You may also find it helpful to sit down for around 20 minutes after a meal and rest, rather than getting straight back to work or other activities.
ComplicationsComplications are when problems occur during or after the operation. Most people aren’t affected. The possible complications of any operation include an unexpected reaction to the anaesthetic, excessive bleeding or developing a blood clot, usually in a vein in the leg (DVT).
Being very overweight increases the risk of complications following any operation. You’re more likely to have complications from having a general anaesthetic and are more at risk of developing blood clots. If you have other conditions linked to your weight, such as high blood pressure or diabetes, then these can also increase your risk of developing complications.
Complications specific to a gastric bypass operation can include:
an infection in your wound or a chest infection
a blood clot in your lung (pulmonary embolism)
a leak at the place where your intestine is re-joined to your stomach. This can be serious and will need surgery to repair it straightaway
a lack of protein, vitamins and minerals caused by the change in the amount and type of food you’re able to eat after the operation. This can affect your general health. Vitamin and mineral supplements and a high protein diet can help to prevent this If you lose weight quickly, you may develop gallstones. These can be painful and you may need surgery to remove them. Your surgeon may advise removing your gallbladder when you have your operation or prescribe a medicine called ursodeoxycholic acid to reduce your risk. Always ask your surgeon for advice and read the patient information leaflet that comes with your medicine.
During your operation your surgeon may come across an unexpected problem and may need to convert the keyhole operation to an open procedure. This won’t affect how well the operation works, but it may take a longer time for you to recover afterwards.
Not everyone loses enough weight after gastric bypass surgery. If this happens your surgeon may suggest another operation.
The exact risks are specific to you and will differ for every person, so we have not included statistics here. Ask your surgeon to explain how these risks apply to you.