CT Virtual Colonoscopy

Introduction

This is an examination of the colon (large intestine) and is performed in a CT scanner which takes a series of images of your body in cross-section. A powerful computer takes these images and builds a 3-dimensional display of your large intestine for viewing and assessment by the radiologist.

The scan is specifically designed to look at the colon – however, it is possible that abnormalities in other organs in the abdomen may be detected which may require further investigation. If this happens it will be reported to your doctor who will discuss the matter further with you.

What you must tell us

  • If you suffer from abnormal heart rhythm you may not be suitable for an injection
  • If you are a diabetic or have kidney failure
  • If there is any possibility that you may be pregnant

Preparation

Before the colonoscopy your bowel needs to be prepared so that it is free of faecal material for this examination – this means you need to have a special low residue diet and laxatives prior to the scan. Please contact one of our clinics to arrange your preparation and appointment time.

TWO days before examination

You must stop eating all fruits including: fruit yoghurts, nuts plus any food containing fruits.

ONE day before examination

No solids foods, no milk or milk products allowed. Drink only *approved clear liquids for breakfast, lunch and dinner. At 12pm drink 250mls of Readi-Cat (Barium.)

At 5:00 pm

Mix sachet of ColonLYTELY with one (1) litre of water. Over the next hour or so, drink a glassful of this solution every 10 to 15 minutes. If you feel nauseous or bloated, slow down and drink a glassful every 20 minutes, until it has been completed. You will have loose motions within 1 to 3 hours.

At 6:00 pm

Add the entire contents of one (1) sachet of PICOLAX into a glass of chilled water (approx. 120 mls). Stir until effervescence ceases. Drink the mixture gradually and completely. This can be followed by as many glasses of water or *approved clear fluids as desired in order to satisfy thirst.

At 7:00 pm

Add the entire contents of one (1) sachet of PICOLAX into a glass of chilled water (approx. 120 mls). Stir until effervescence ceases. Drink the mixture gradually and completely. This can be followed by as many glasses of water or *approved clear fluids as desired in order to satisfy thirst. This preparation may cause multiple bowel movements. It usually induces frequent loose bowel movements within only three (3) hours of taking a dose. Please remain within easy reach of toilet facilities. Some intestinal cramping is normal. Drink only *approved liquids for dinner.

DAY of examination

From midnight, sips of clear fluid can be taken to quench thirst.
* Approved clear fluids

  • Water
  • Bonox
  • Lucozade
  • Fruit cordials
  • Clear bouillion
  • Clear fruit juices (apple)
  • Black tea or coffee (no milk)
  • Barley sugar
  • Clear broth

Unless you are a diabetic, please have barley sugar, liquid glucose or some form of sugar drink during this preparation. Individual responses to laxatives do vary.

During the Procedure

A small tube will be inserted into your rectum and through this a gas will be introduced into the colon to distend it. This is an important part of the examination since the colon needs to be adequately distended for the scan to be accurate. The distension may cause some discomfort but it is important that you try to ‘hold-on’ to the gas – the scan only takes a few minutes after which you will be able to release the gas. You will be monitored by our staff and should you need help, they are trained to give you all the assistance you require.

Do I have an injection?

You may be given a small injection which will help you ‘hold-on’ to the gas and ease any discomfort you may feel.

A consent form will be given to your prior to the examination explaining the procedure. Sedation is not used for the scan which means that you should be fit to drive soon after the examination. However, you may prefer to bring along a friend or partner to escort you.

Are there any side effects?

Rarely, some people feel light-headed during or after completing the bowel preparation and, in rare instances this may lead to fainting. This risk is minimised by a plentiful fluid intake. It is theoretically possible that bowel perforation (a hole in the bowel) could occur but this risk is estimated at less than 1 in 30,000. You will be exposed to a small dose of x-rays, however it is unlikely to cause harmful effects.

How long will the procedure take?

Most examinations are completed within thirty (30) minutes, although attendance at the clinic may take a little longer. On completion of the procedure the information from the scan is processed by the computer to produce the 3-dimensional image. This is a complex exercise and can take some time but there is no need for you to wait as the results will be sent to your referring doctor. Since not all our clinics offer this examination, when you make your appointment our staff help you decide which is the most convenient for you.

Please bring any previous imaging with you on the day of your examination. If you have any questions please do not hesitate to ask us!

Information brochure

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Locations where this service is available