Whakamātaunga kōpiro Colonoscopy

During a colonoscopy, a specially trained doctor or nurse looks directly at the lining of your large bowel (colon), using a very small camera. A sample (biopsy) can be taken from your bowel and small polyps can be removed during the procedure.

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When you would have a colonoscopy

You may need a colonoscopy if you have unexplained bowel symptoms. These include:

  • a change in how often you pass a poo (bowel motion)
  • ongoing runny poos (diarrhoea)
  • blood with your poo
  • tummy (stomach) pain. 

You may also need a colonoscopy if you:

  • have had a positive test result as part of the National Bowel Screening Programme
  • have had previous bowel polyps or bowel cancer
  • are at increased risk of bowel cancer, such as having a family history of bowel cancer
  • have an unexplained low red blood cell count (anaemia) due to low iron levels.

Having a colonoscopy

Colonoscopy is usually a day procedure performed in hospital. You will be awake during the procedure.

  • You will be given medicine that makes you sleepy and helps make you comfortable during the procedure.
  • A special thin, flexible tube with a camera (colonoscope) is passed into your large bowel through your bottom (anus).
  • Air is pumped into your bowel to make things easier to see.
  • The colonoscope is passed through your large bowel. It provides video images which are displayed on a screen.
  • Sometimes the colonoscope is used to take a sample (biopsy) of the bowel or remove small polyps.

A colonoscopy usually takes 30 to 45 minutes. It can take longer if you need a biopsy.

Before and after your colonoscopy

Before you have your colonoscopy, your bowel needs to be emptied so your bowel lining can be clearly seen.

Instructions on how to do this will be included with your appointment letter. As part of this you will need to:

  • follow a special diet for a few days
  • take medicines to clear your bowel (laxatives).

You may need to stop some of your usual medicines. You should get instructions on this. Check with the healthcare provider who will be doing your procedure if you are unsure.

After your colonoscopy you will be able to eat and drink as normal.

You will not be able to drive for at least 12 hours.

Colonoscopy risks

Colonoscopy is usually a safe procedure. However, as with most medical procedures, problems can sometimes happen.

There is a small risk the colonoscopy procedure itself, or the removal of polyps, will cause bleeding or damage to your large bowel. If this happens, you may need further treatment.