Understanding conventional and virtual colon checks

If you've visited your GP with symptoms of bowel cancer, you may be about to undergo a colon check. Symptoms of bowel cancer can include blood in faeces, abdominal pain and persistent changes in bowel habits, and while these conditions don't necessarily mean bowel cancer is inevitable, checks are important in order to establish whether you have the disease. However, while regular colon checks involve the insertion of a tiny camera into the bowel, doctors can carry out virtual colon checks too. Some people, however, may be unaware of the differences between the two screening processes.



A conventional colon check, or colonoscopy, traditionally involves the placement of a tiny camera into the large bowel. It sounds like an uncomfortable process, but a colonoscopy camera - known as a colonoscope - is narrow and flexible, and its tube-like shape allows it to be inserted into the bowel as easily as possible. The day before a colonoscopy procedure, patients are usually asked to stop eating solid food, consume plenty of clear fluid and take a strong laxative, which may necessitate remaining close to a toilet at all times. Essentially, a traditional colonoscopy allows your doctor to look directly into the large bowel on a monitor and allows for sensitive checking of polyps, inflammation and early signs of bowel cancer.

A virtual colon check, on the other hand, does not involve the insertion of the colonoscope. Instead, it uses X-ray technology to create a 3D image of the large bowel. Like a conventional colonoscopy, it detects polyps and abnormalities on the bowel wall and helps in detecting the early signs of bowel cancer, as well as investigating other bowel-related diseases.



Since a telescopic camera is not used in the process, preparing for a virtual colon check is slightly different to the traditional method. A special diet may need to be followed in the days before the procedure and a laxative may be administered. However, you may also need to swallow a 'contrast agent', which is an iodine-based dye that will help your bowel appear more accurately on the scan.



A virtual colonoscopy may be preferable for patients who are apprehensive about colonoscope insertion, or may be recommended for at-risks groups that are required to have a colon check on a regular basis. However, there are alternative tests that can be carried out, though their detection rate is arguably less effective. A sigmoidoscopy, for instance, is like a conventional colonoscopy but only examines the lower bowel, while a barium enema - which involves the insertion of a fluid containing barium into the bowel via the rectum - assists the visibility of the bowel on X-ray images.