What is CT colonography?
CT colonography (CTC), also known as a virtual colonoscopy, is a minimally invasive imaging test that examines the inside of your bowel using a specialised CT scanner. This test provides detailed 2D and 3D images of your colon and rectum, helping to diagnose conditions such as:
Unlike a traditional colonoscopy, CTC does not require the insertion of a camera into the bowel, making it a quicker and less invasive alternative for some patients.
Do you need any preparation beforehand?
For the scan to produce clear and accurate images, your bowel must be completely empty. You will receive:
- Laxative sachets (usually Picolax) to take the day before the procedure
- Instructions to avoid eating or drinking from midnight before the examination
- Guidance on taking normal medications—you can usually continue them as usual
Proper bowel preparation is essential for a successful scan, so following the instructions carefully is important.
What does the CT colonography scan involve?
- Changing into a hospital gown—you may be asked to remove some clothing for the scan
- Placing a cannula—a small tube (cannula) is inserted into a vein in your arm to allow the contrast dye to be given, improving the visibility of your organs and blood vessels
- Inflating the bowel—a small tube is gently inserted into your rectum to introduce air, expanding the bowel for clearer images
- Administering an injection—a muscle relaxant (Buscopan) is sometimes given to relax the bowel and reduce cramping
- Scanning process—you will lie on a moving examination table, which passes through the doughnut-shaped CT scanner. The machine will take hundreds of cross-sectional images, which are reconstructed into 3D images to provide a detailed view of your bowel
The procedure is quick and painless, usually lasting around 15 to 20 minutes.
What happens after the test?
- You can eat and drink normally once the scan is complete
- You may experience mild bloating or wind-like discomfort, but this usually settles quickly
- The scan results will be reviewed by a specialist, and a detailed report will be sent to your consultant
If polyps or abnormalities are found, your consultant may recommend a colonoscopy for further assessment or biopsy if needed.
What are the benefits of CT colonography?
- Less invasive than a traditional colonoscopy—no need for a camera to be inserted into the entire bowel
- Highly detailed 3D imaging—helps to detect polyps and cancers at an early stage
- Short procedure time—typically takes around 15 to 20 minutes
- Minimal recovery time—no sedation is required, so you can resume normal activities immediately
CTC is an excellent alternative to colonoscopy for patients who are not suitable for an endoscopic procedure or prefer a less invasive option.
Are there any risks?
CT colonography is a safe and commonly performed test. However, there are some minor risks
- Mild bloating or cramping due to the air introduced into the bowel
- Rare allergic reaction to the contrast dye (inform your doctor if you have any allergies)
- Minimal radiation exposure, similar to other CT scans
If you experience severe pain, unusual bleeding, or allergic reactions, contact your healthcare provider immediately.
Why choose the Midlands Bowel Clinic?
At Midlands Bowel Clinic, we provide
- Expert consultants specialising in bowel imaging and diagnostics
- State-of-the-art CT technology to ensure the highest quality imaging
- Comprehensive bowel assessments to detect and diagnose conditions early
- Personalised treatment plans tailored to your symptoms and health needs
Contact us
If you have symptoms such as persistent bowel changes, rectal bleeding, unexplained weight loss, or abdominal pain, CT colonography could provide crucial insights into your bowel health.
