Results vs risks of the procedure


There are a number of reasons why your doctor may recommend a colonoscopy. Screening for colon cancer is one of the main reasons, particularly in people with a family history of colon cancer or other risk factors.

Colon cancer is very treatable, provided it’s detected early. Studies show that colonoscopy has a high degree of accuracy in detecting colon cancer and can reduce deaths from colon cancer by between 60 and 70%

The accuracy of the results can vary depending on how good your bowel preparation has been and how well the procedure is done.


As with any medical procedure or investigation there are some risks. The chance of complications depends on the type of procedure and other factors, including your general health. The most common complications are:

  • Intolerance to the bowel preparation medication. This is unusual but can cause headaches or vomiting.
  • Bloating after the procedure because air has been pumped into your colon. Most endoscopy units these days use CO2 gas which makes this less likely.
  • Bleeding. The risk of bleeding is less than 1 in 100. Bleeding may occur during the removal of a lesion or polyp. Having multiple lesions removed can increase the risk of bleeding. Bleeding usually stops spontaneously, but if it happens you may have to stay in hospital for observation and may need further treatment.
  • Perforation of the colon. The risk of a perforation (or small hole) in the colon is less than 1 in 1,000. If this happens, you’ll need to stay in hospital for observation and it’s likely you’ll need surgery to repair your bowel.
  • Other possible complications include abdominal pain, nausea, vomiting, reactions to the sedation and, rarely, injury to your spleen.


How to find a gastroenterologist or surgeon to perform your colonoscopy.

important information

Information is provided by HCF in good faith for the convenience of members. It is not an endorsement or recommendation of any form of treatment nor is it a substitute for medical advice, and you should rely on the advice of your treating doctors in relation to all matters concerning your health. Ever effort has been taken to ensure the accuracy of the information, however HCF takes no responsibility for any injury, loss, damage or other consequences of the use of this information.