There are many private companies that provide
advanced methods of screening. One such method is the
Computerised Tomography (CT) is a sophisticated X-ray technique
used to produce detailed internal images of the body. CT
colonography uses CT to take multiple images of the large bowel.
These can be 2 or 3-dimensional. This newer test is sometimes
called a Virtual Colonoscopy, but is not widely available on the
The preparation is the same as if you were having a colonoscopy.
The test is done in the CT department and carried out by a
radiographer. Before the procedure takes place you will be given an
injection into your hand which relaxes your bowel. You may also be
given an injection of a dye into a vein in the arm to enhance the
scan images. Just before the CT scans are taken the doctor will
pass a tube into your back passage and pump in some air and gas to
inflate the bowel this helps to give a clearer picture. You will be
asked to lie on a padded couch on your back and then your front
whilst you pass through the scanner. This procedure can be used as
an alternative to conventional, invasive colonoscopy but does not
rule out the possibility of a subsequent colonoscopy should
abnormalities be found.
This type of scanning produces 3D moving fly-through views of
the bowel and also static images of the outside of the bowel wall
and the surrounding area. It can pick up abnormalities missed by
more conventional methods of viewing the bowel. Results will
usually be available from your referring doctor within 48 hours of
There is still the need to prepare the bowel for a virtual
colonoscopy. This will mean following a change in your diet for two
days before your appointment and taking a laxative.
A colonography is provided via the private health care sector,
though the costs may be covered by your health insurance. You do
not have to be referred by your GP and you can elect to undertake a
colonography as part of a personal health check. Two companies that
provide these services are listed in the related links section on
this page. Both are making donations towards our work.
Page last reviewed 12th January 2011.