Colonoscopy in Brisbane

Our open access colonoscopy is a flexible fibre-optic scope examination of the colon and rectum that is synonymous with the large bowel. This is a non-surgical procedure and allows visualisation of the internal aspect of the bowel and in particular identification of certain conditions and potential pathology. It also allows procedures to be performed such as biopsies and polyp removal. Whilst the last part of the small bowel, otherwise known as the terminal ileum can be visualized, further passage of the scope is generally not feasible nor is it generally necessary as conditions affecting this part of the bowel are unusual.

The procedure takes about 30 minutes. The procedure will take place in Brisbane and be performed by Dr Renaut. In order to obtain a clear view at the time of the procedure all faecal material should be removed from the colon and rectum. This is achieved by altering the diet and taking a preparation, otherwise known as a bowel prep. You will be restricted to clear fluids only for the whole day prior to your procedure up to midnight. From midnight through to 2 hours prior to the procedure you can drink water only and from then on, until after the procedure you must be nil by mouth. You will receive specific instructions about this well in advance of the procedure, including an admission time and an approximate time for the procedure itself. Additionally, comprehensive instructions, including potential side effects, are available.

What about my usual medications?

In general, these should all be taken as usual with a sip of water. Exceptions will include:

  • Warfarin or other blood thinning drugs
  • Insulin or other diabetic tablets.
  • Iron supplements.
  • Any herbal and naturopathic drugs - many of these contain unidentifiable substances in unknown quantities that make them potentially unsafe. You will need to check with the manufacturers as to what these contain. 

These should be ceased in accordance with specific instructions issued by Dr Renaut’s office.

It is also necessary to inform the anaesthetist on the day of all medications, past medical history and any allergies. Please bring your medicines with you on the day to Brisbane Private or Northwest Private Hospitals so that we can confirm the drugs that you are taking. If you suffer from chronic sleep apnoea bring your CPAP machine with you.

Alternatives to our Brisbane colonoscopy procedure

There are other methods available for visualizing the large bowel. These are a barium enema and a special CT scan. Whilst these are generally of a lesser inconvenience to the patient in that they do not require sedation they have the draw back that they are less accurate in identifying certain conditions than a colonoscopy and they are purely diagnostic procedures. If biopsies are required to be taken or polyps removed the patient will then require a colonoscopy to achieve this.


There are numerous indications for performing a colonoscopy. The reasons in your particular case will be fully discussed prior to the procedure.

Will I be asleep during the procedure?

A light anaesthetic will be administered for the colonoscopy procedure, sometimes referred to as a twilight sedation, and your anaesthetist will discuss this and any potential complications on the day.

An anaesthetist will be present and you will have the opportunity to discuss this further with him/her. Although it is not normally described as a general anaesthetic, you will be heavily sedated and often will not recall the procedure.

What are polyps?

A polyp is an abnormal growth, usually benign (non-cancerous) on the inner lining of the bowel. Larger polyps may turn cancerous with time although this process usually takes several years. Removing polyps in those at risk is therefore an important means of preventing bowel cancer.

What if something abnormal is found?

If possible, it will be dealt with at the time of procedure. Polyps can often be removed, but if it is too large or if a cancer is found, biopsies can be taken.

How will I know what is found at the colonoscopy?

Your Brisbane surgeon Dr Renaut will speak with you and/or your family members immediately after the colonoscopy. The results of any biopsies will be available a few days later and this information will be passed on to you by phone or Dr Renaut will see you for a follow up as necessary. He will send you home with a formal report which is a copy of the report that he sends to your referring doctor and/or GP. He will also discuss with you the need for a repeat examination.

How accurate is a colonoscopy?

No investigation in medicine is perfect, but a colonoscopy is generally very good at identifying the things that are important. Studies have shown colonoscopies to be more accurate than barium enema but up to 3% of cancers can be missed. Small polyps can be missed in 6% of cases. Sometimes it is not possible to safely remove a large polyp and under these circumstances a bowel resection at a later date may be necessary. Very rarely it may fail to identify a potential source of bleeding. In about 2% of cases it is not possible to pass the scope through the whole length of the colon. This is usually due to anatomical variation. Under these circumstances, it is safer to abandon the procedure and to proceed to a special scan that can examine the part of the colon that has not been seen at colonoscopy.

No investigations in medicine are perfect. Studies have shown colonoscopy to be more accurate than barium enema but up to 3% of cancers can be missed. Small polyps can be missed in up to 6% of cases. CT colonography is still being evaluated and radiological procedures have the downside that a colonoscopy will still be required if any abnormality is found.

What are the risks?

Colonoscopy is a frequently performed and safe procedure. Complications are uncommon. Most studies report a complication rate of less than 1 in 1000 examinations. The risks tend to be increased when polyps are removed. Important complications include:

  • Perforation of the bowel - this is usually evident soon after the procedure and may require emergency surgery. It is rare.
  • Bleeding can occur. This may be from the site of the polyp or biopsy, or related to treatment for haemorrhoids. Very rarely, a blood transfusion may be required and surgery is only necessary in extreme cases.
  • Complications related to sedation are also uncommon.

A significant complication of colonoscopy is perforation of the bowel. This is rare. It occurs in about 1 in 10,000 colonoscopies but the rate increases if once again polyps are removed. If a perforation does occur, it is often identified at the time. Alternatively, the patient may present several hours later with abdominal pain and signs of early peritonitis. This will almost certainly require an operation to repair the perforation which may involve a bowel resection and temporary colostomy but it should be stressed this is a rare occurrence.

Injury to other organs that are in close proximity to the colon, in particular the liver and spleen, can be injured, purely by process of pressure from within the colon. This has on occasion resulted in bleeding from that organ which may require an operation such as splenectomy. This is exceedingly rare.

Because the anaesthetic is light, complications relating to this are rare and are very much related to the existence of other conditions such as heart disease, chest disease, diabetes and obesity. As mentioned your anaesthetist will discuss these issues with you on the day, prior to the procedure.

Further Questions

For most patients, the procedure is not nearly as unpleasant as they had imagined or been told by friends or relatives. Please contact our Brisbane rooms if you have any questions. There will be a further opportunity to speak to Dr Renaut prior to the procedure.

Post-operative Care following a Colonoscopy procedure

Your Brisbane specialist will speak with you immediately after the procedure. The results of any biopsies taken will be available a few days later and this information will be passed on to you by phone or in a follow up consultation as necessary. You will be sent home with a formal report that is a copy of the report that is sent to your referring doctor and/or G.P.

Effects of Sedation and Safety Issues

Once you have been given the all clear by the recovery staff to be discharged it is imperative you go home with a friend or family member and rest for the remainder of the day. Even though you may feel ok after the procedure, small amounts of sedative will remain in your bloodstream. For this reason, you must not drive a car or operate machinery for 24 hours after the procedure. Failure to follow this advice carries the same implications as drink driving and is against the law. You should also not sign any contracts or legal documents for 24 hrs. You should not consume alcohol as the sedative effects will be increased. You should be cautious with simple tasks around the house, e.g. using knives etc. You must be taken home and cared for overnight by a responsible adult.

The following day you should be completely back to normal and ready to resume your day to day activities.

Bowel function returns fairly quickly in particular the passage of flatus. A normal diet can be resumed almost straight away unless there are specific instructions to the contrary. If you do suffer one of the unusual complications such as excessive bleeding or pain or if you feel unwell, for more than a few hours then you should not hesitate to contact your specialist or G.P.

What can I expect after the colonoscopy?

The colon is inflated with air to distend it so that a good view can be obtained. Most of this air is sucked out upon withdrawal of the scope but a small amount of retained gas can cause a bloated feeling and some crampy "wind" pains. This usually passes quickly but may persist for a few hours. You will be able to have a light meal as soon as the sedation has started to wear off. Severe pain is not expected and you need to contact Dr Renaut if this is the case.