CT colonography

CT colonography is still being researched as a way of diagnosing bowel cancers| and it isn’t widely available, so if you need one you may have to travel to a specialist centre. Your doctor or nurse can give you more information about this test.

Instead of having a colonoscope put into your bowel, a computer uses CT scanning images to examine your bowel. A CT scan takes a series of x-rays, which builds up a three-dimensional picture of the inside of the body. The CT scan uses a small amount of radiation, which is very unlikely to harm you and won’t harm anyone you come into contact with.

The preparation is the same as if you were having a colonoscopy, so you’ll be asked to drink fluids and take a laxative a day or so before the scan. CT colonography takes place in the hospital CT scanning department and can usually be done as an outpatient.

Just before the CT scans are taken, the doctor passes a tube into your back passage (rectum) and pumps in some air and gas (carbon dioxide). This expands the bowel and helps to give a clearer picture. You may also be given an injection of a dye, which allows areas of the bowel to be seen more clearly. This may make you feel hot all over for a few minutes.

It’s important to let your doctor know if you’re allergic to iodine or have asthma, because you could have a more serious reaction to the injection.

You’ll have two CT scans – one lying on your back and one on your front. The computer then matches up the two scans to create a virtual image of the inside of your bowel.

Waiting for your test results

It will probably take several days to a couple of weeks for the results of your tests to be ready. Waiting for results can be a difficult time and you may need support from one of our cancer support specialists|.