What Is A Colonoscopy?

This is a procedure whereby a thin, long and flexible tube with a camera at the tip is inserted through the bottom to examine lower gastrointestinal structures. These include the rectum, the colon (large bowel) and the terminal ileum (the last part of the small intestine). The procedure is done by a certified endoscopist (your doctor) under sedation (light or deep sleep) by a Consultant Anaesethetist.

The procedure may be:

  • Diagnostic: this will involve thorough examination and visualisation of the structures as well as tissue sampling (biopsies) of any relevant areas

  • Therapeutic: treatment of tissue bleeding or narrowing or growths (polyps)

Why Do I Need A Colonoscopy?

A colonoscopy may be recommended if you have experienced the following signs or symptoms:

  • Per rectum bleeding

  • Diarrhoea

  • Altered bowel habits

  • Abdominal pain or discomfort

  • Urgency or difficulty passing bowel motions

  • Iron deficiency

  • Weight loss

It may also need to be done as part of regular assessment if you have a history of:

  • Colonic polyps

  • Inflammatory bowel disease (ulcerative colitis or Crohn's disease)

  • Colorectal cancer in yourself or within the family

How Can I Prepare for A Colonoscopy?

In order to empty the colon and maximise visualisation of the bowel, you will be required to take a specific volume of solution, known as bowel preparation, in the 24 hours prior to your procedure. It is essential that you follow the instructions regarding the timing depending on whether the colonoscopy is in the morning or afternoon, and to ensure you are fasted at least six hours prior to the colonoscopy. If you have any medical conditions or regular medications (such as diabetic or blood-thinning medications), please discuss these in detail with your team as this process may affect the timing of your regular medications and require coordination.

Are There Any Risks Or Side Effects From A Colonoscopy?

Please be assured that the doctors performing your procedure are highly qualified and certified by the appropriate governing gastroenterological and endoscopy society. Complications from this procedure have been documented although they are uncommon and often rare. If you are undergoing a colonoscopy for therapeutic purposes, these may be more common.

Risks that we routinely consent for include:

  • Anaesthetic complications such as allergy or reaction to the medications, breathing or heart problems, lung infections and stroke

  • Bleeding

  • Missed polyps or lesions

  • Perforation or tearing of the structures traversed by the scope which may need hospitalisation and surgical repair, with potential need for stoma formation

  • Need to abandon procedure or incomplete procedure

If you are concerned about any of these potential adverse events or wish to explore these further, please discuss this with your doctor. If you experience any new or troubling symptoms after the procedure, please also get in touch with the medical team immediately.

Additional Information

For more information on bowel preparation, please refer to the Links page. For more information on colonoscopy procedures, please speak to your responsible consultant or access the Gastroenterological Society of Australia (GESA) Fact Sheet: Colonoscopy Information.