What is a colonoscopy?

A colonoscopy is a procedure that is used to inspect the inside of the large bowel (colon). It is performed using a long flexible tube (colonoscope) with a light and camera on the end to diagnose and sometimes treat conditions of the colon. During the procedure the gastroenterologist may take small tissue samples (biopsies), which can then be inspected under a microscope by an expert pathologist, or remove polyps (abnormal tissue growth), which have the potential to transform into bowel cancer.

What is the reason for having a colonoscopy?

Colonoscopy is used to diagnose conditions of the large bowel and may be needed in patients experiencing bleeding from their rectum, unexplained abdominal pain, weight loss or change in bowel habit with diarrhoea or constipation. It also allows the removal of polyps and thereby reduces the risk of bowel cancer.

Are there alternatives to colonoscopy?

Depending on the clinical scenario, there are some other tests which can be used including:

  • Faecal occult blood test. This tests for the presence of traces of blood in the stool and is used as a screening test for bowel cancer. It is not as sensitive as a colonoscopy but is utilised in low risk patients. If positive, it needs confirmation with a colonoscopy.
  • CT colonography: This is a type of CT scan that inspects the  the colon. A CT colonography may be used in patients in whom a colonoscopy was either incomplete or unsuccessful. This test requires bowel preparation prior to the scan.

What preparation is required prior to the procedure?

Bowel preparation is required to clear out the colon prior to the procedure to allow for an accurate and thorough assessment. The preparation involves dietary changes and strong laxatives.

Preparation instructions

Morning procedure

Afternoon procedure

What are the risks of colonoscopy?

Colonoscopy is generally a very safe, well tolerated procedure and
major complications are very rare, but can include:

  • Bowel perforation:  This involves damage through the bowel wall. In some instances this can be repaired immediately during the procedure while in other cases may require surgery. The estimated risk of this complication is approximately one in every 1000 cases.
  • Bleeding: A small amount of bleeding is not unusual after a biopsy of bowel wall or the removal of a polyp, and settles spontaneously. However in approximately one in every 2000 cases the bleeding may be severe enough to require hospitalisation and possibly a procedure to stop the bleeding.
  • Missed polyp: While a colonoscopy is the best test to find polyps, very small polyps (less than 5mm) may be missed in up to 25% of cases. The rate of missing larger polyps (greater than 1cm) is approximately 2%. A poor bowel prep is one factor that can lead to polyps being missed.
  • Failed procedure: This refers to when the colonoscopy cannot cannot be completed due to areas of severe narrowing, diverticular disease, or looping of the colon. This may require a repeat attempt at a later date or a CT colonography as an alternative. If the bowel prep is very poor, the procedure may also have to be repeated.

What do I do with my usual medications?

If you are taking any blood thinners including warfarin, clopidogrel (Isocover, Plavix), rivaroxaban (Xarelto), apixaban (Eliquis), dabigatran (Pradaxa) or ticagrelor (Brilinta) please let the staff at Yarra gastroenterology know at least 7 days prior to the procedure. It is also important to inform us if you are taking diabetic medications including insulin as the doses will need to be adjusted prior to the procedure.

Most regular medications can be taken with a sip of water early in the morning prior to the procedure.

What do I bring to the procedure?

Please bring a copy of your doctor’s referral, private health fund details and medicare card. Wear loose fitting clothing. You will be asked to change into a gown prior to the procedure. Please leave any valuables or jewellery at home.

What can I expect at the hospital before the procedure?

You will be met by both the anaesthetist and gastroenterologist prior to the procedure and will be asked some basic questions regarding your health and medications.

What happens during the procedure?

Your comfort and wellbeing will be monitored throughout. You will be lying on your side for the procedure and the anaesthetist will place a small cannula  in the back of your hand through which  a sedative will be given. The colonoscope will be inserted via the rectum and then all the way all the way around the colon to the point it joins the small bowel. The bowel will be thoroughly inspected and if necessary biopsies will be taken and polyps removed. This whole process takes between 15-30 minutes.

What happens afterwards?

You will be monitored until you are awake and alert. The gastroenterologist will speak to you to explain the results. You will be given a light snack and water to drink. You may be slightly drowsy for a number of hours following the procedure due to the sedation. You will be able to leave approximately 1-2 hours after the procedure and will require a friend or family member to collect you. You are advised not drive until the following day and also not operate heavy machinery for 24 hours. You can take your regular medicines following the procedure unless otherwise notified.