During the test, a short, thin tube is placed inside your rectum to fill your colon with air. The air will inflate and open the colon, helping to make any polyps or tumours easier to see. After the air has inflated the colon, you will go through a CT scanning machine which will take about five minutes.
The test is not painful but the gas used to inflate the colon can make you feel bloated, as if you have trapped wind. The procedure is generally more tolerable and has fewer risks than a colonoscopy.
If cancer or a pre-cancerous polyp is detected, a colonoscopy will be needed to biopsy the tumour and/or remove the polyp.
Some patients are concerned about excessive exposure to radiation from the CT scanner. The amount of radiation received from a CT colonography is similar to that we absorb from the atmosphere in one year.
Discuss with your doctor whether CT colonography is the right test for you.
Developed with the assistance of Dr Adrian Balasingham, Consultant Radiologist at Canterbury DHB and Christchurch Radiology Group.