The risks associated with gastric bypass surgery

Gastric bypass surgery is generally a safe operation. However, in order for you to make an informed decision and give consent for the operation, you need to be aware of the possible side-effects and the risk of complications of this procedure.

The side effects


These are the unwanted, but mostly temporary effects of a successful treatment.

You are likely to have some bruising, pain and swelling of the skin around the healing wounds.

You may feel or be sick after eating, especially if you try to eat too much. If you eat too many sugary foods you can get an unpleasant sensation, called "dumping", which may make you feel sick or faint, or give you diarrhoea. You should drink plenty of fluids until the feelings have passed, and you should also reduce the amount of sugary foods you eat.

In the long term, your restricted diet may cause some shortage of nutrients like iron, calcium and vitamins, so you may need to take multivitamin/mineral tablets indefinitely.

Associated complications


Complications are problems that might occur during or after the operation.

Most people will not experience any serious complications from gastric bypass surgery.

As with any operation, there are risks associated with having a general anaesthetic. The possible complications include an unexpected reaction to the anaesthetic, excessive bleeding or developing a blood clot, usually in a vein in the leg (deep vein thrombosis, DVT) or in the lungs (pulmonary emboli, PE). The risks increase for people who already have other medical conditions, such as heart disease or high blood pressure.

Some of the complications you may get after a gastric bypass operation are listed here:

Infection - antibiotics are usually given during surgery to prevent infection.
Damage to other organs in your abdomen - you may need further surgery to repair any damage.
Anastomotic leak (join) - the point where your intestine is re-joined to your stomach pouch could leak in the first few days and you may need further surgery to repair this.
Anastomotic stricture or ulceration (join) - the point where your intestine is re-joined to your stomach pouch could narrow or form ulcers after surgery and you may need endoscopy with or without dilatation or further surgery to fix it.
Internal herniation and adhesion problems - you may need further surgery for it.
Gallstones - there is a risk you may develop gallstones if you lose weight quickly. These can be painful and you may need surgery to remove them.
Failure to lose weight - it's possible you may fail to lose sufficient weight or regain weight you have lost after bypass surgery.
There is a chance your surgeon may need to convert your keyhole procedure to open surgery. This means making a bigger cut on your abdomen. This is only done if it's impossible to complete the operation safely using the keyhole technique.

The exact risks of gastric bypass surgery are specific to you and will differ for every person. Overall, there is a 2-5% risk of adverse effects (as listed above) and a 1 in 200 (0.5%) risk of death caused by having this operation.

For further information regarding obesity or weight loss surgery, please contact Mr Sanjay Agrawal, Consultant Bariatric Surgeon at www.londonobesityclinic.co.uk or on telephone at 07876 618424.

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