CT Colonography is sometimes called CT Colonoscopy or an abdominal CAT scan.
What is a CAT scan? In this situation, it is a special x-ray test used to visualise the bowel and abdomen.
It can detect polyps and tumours (cancers) in the large bowel. It also shows other pathologies that can cause bowel upset although this isn't its primary use.
It is particularly useful for people that are not fit enough for colonoscopy.
The test shows the inside of the large bowel using x-ray 'slices'. The cat scan procedure is quite quick, only taking about 15 minutes to perform.
To perform your CAT scan procedure, the radiologist will need you to take a bowel preparation to clear out the bowel.
This is normally with a laxative in the 24 hours before the test, taken in a similar way to colonoscopy preparation.
On the day of the CT colonography examination, you will be positioned on a special table which will then be used to place you in the scanner.
Prior to this, a tube will be popped into your bottom, through which air or carbon dioxide will be passed to inflate the large bowel. X-rays will then be passed to take 'pictures' of the large bowel.
The abdominal CAT scan images are interpreted by a radiologist and the results are then normally sent to your doctor.
Complications are fortunately very rare. There is a very small risk of perforation or putting a hole in the bowel wall. The risk is a lot less than colonoscopy though.
If this happens then it can make you very unwell with abdominal pain, sickness and fever.
Another potential risk is bleeding due to trauma from the tube that is inserted in your rectum. This is usually minimal.
The main disadvantage is that the test only gives you pictures of your bowel. If you have a polyp then this will need to be removed, usually by colonoscopy at a later date, as they can become cancerous.
Also, if there is a tumor present, this will usually need to be biopsied (tissue sampled) to confirm the diagnosis, again normally by colonoscopy.
There is a small risk from radiation, but not a big risk.
I hope you now have a better understanding of what a CT Colonography and or CT colonoscopy is now.