What are the risks of Gastric Bypass Surgery? - Obesity Surgery Guide


This type of weight loss surgery is tried and tested and is recommended for chronic weight problems such as obesity.  It is however, a highly complex procedure and as such does carry some risks.  All surgery has some risks which are minimal but nevertheless they are there and you need to be aware of these beforehand. 

The risks of this surgery are:

  • Deep vein thrombosis (DVT).  A condition in which a blood clot can form in the lower part of the body such as the leg.  If left untreated it can be potentially fatal.  Often caused by a long period of inactivity.
  • Infection.  The staple lines or incisions can become infected.
  • Pulmonary embolus.  This is the formation of blood clots in the lungs.
  • Leakage.  Fluids can leak around the site joining the intestine to the stomach or at the lower point or ‘Y’ section of the intestine.
  • Marginal ulcers.
  • Stenosis.  This is caused by a narrowing of loop of the intestine or one of the openings.
  • Adverse reaction to anaesthesia and medications.  This can happen in a few rare cases.
  • ‘Dumping syndrome’.  This is the name given to a collection of symptoms which refer to an unpleasant
    condition.  It is caused by the rapid intake of sugary foods from the stomach to the intestine.  In effect, they are ‘dumped’ too quickly from the stomach and as a result of this they cause a large amount of fluid to enter the stomach.  This then causes nausea, vomiting, bloating, diarrhoea, dizziness and heart palpitations.  There are two types of dumping – early, which can happen directly after a meal and late which occurs a couple of hours after a meal. 

The symptoms described above happen with early dumping.  Late dumping happens as a result of a rise in  blood sugar levels which is also due to the intake of sweet, sugary foods.  The symptoms are very similar to those of hypoglycaemia and include shaking, dizziness, sweating, anxiety and a rapid heart rate.

Dumping syndrome can be avoided by reducing your intake of high fat or sugary foods, avoiding drinking any liquids with a meal and eating little and often.  It tends to happen early on after surgery but once the altered stomach and small intestine work better together then it will reduce.  

Death from surgery is extremely uncommon and has accounted for around 0.5% of cases.  

This surgery can be in many cases, a life-saver and will result in dramatic weight loss.  However, you need to be aware of the risks and the fact that obese people face greater risks with anaesthesia due to their excess weight.  This is where a good gastric bypass surgeon will advise you accordingly.

The thing to remember is that the risks of not having surgery and ending up with a reduced life expectancy as a result of obesity are much greater than the surgery itself. 

This surgery will also reduce your risks of any obesity-related illnesses known as ‘co-morbidities’. 

It is a very effective form of treatment but is not a ‘cure’ as such: it is designed to form part of a lifelong programme which includes surgery, diet, exercise, nutritional supplements and support.

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