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CT scans

Virtual colonoscopy vs colonoscopy

A guide comparing CT colonography with conventional colonoscopy - accuracy, comfort, preparation, sedation and what happens if a polyp is found.

What to expect

  • Preparation: Preparation depends on the examination - some scans need a few hours of fasting or oral contrast, and a cannula may be placed for intravenous contrast. Kidney function is checked when contrast is planned.
  • During the test: You lie on a couch that moves through a doughnut-shaped scanner and may be asked to hold your breath briefly. The scan itself takes only seconds to a few minutes.
  • Results: A consultant radiologist reports the scan, typically within 24-72 hours; urgent findings are flagged the same day.
  • Who follows up: The report goes to your referring GP or specialist, who explains the findings and arranges any follow-up.
  • Cost: an indicative cost varies by provider.

About this test

A guide comparing CT colonography with conventional colonoscopy - accuracy, comfort, preparation, sedation and what happens if a polyp is found. It helps you choose between the two when bowel investigation has been recommended.

How to access it privately

You can arrange a private CT scan either with a referral from your GP or specialist or, in many cases, by self-referring as a self-pay patient after a clinical questionnaire is reviewed. Routine NHS diagnostic waits are often long - frequently measured in months - whereas private slots are typically available within days to around two weeks. Costs vary by provider and should be confirmed with the provider before booking.

Frequently asked

Common questions about Virtual colonoscopy vs colonoscopy.

Quick, plain-English answers to what people ask us most.

  • What is Virtual colonoscopy vs colonoscopy?

    Virtual colonoscopy vs colonoscopy is a diagnostic test used to look at a specific part of the body or how it is functioning, helping doctors reach a clear diagnosis. It is usually requested when symptoms, an examination finding, or an earlier test result needs further investigation. Your doctor can explain exactly why it has been suggested in your case.

  • Why would a doctor order Virtual colonoscopy vs colonoscopy?

    Doctors typically request this test to confirm or rule out a suspected condition, investigate unexplained symptoms, or monitor something that has already been diagnosed. It gives more detailed information than a standard examination alone can provide. The result helps guide what treatment or further investigation, if any, is needed.

  • Do I need to prepare for Virtual colonoscopy vs colonoscopy?

    Preparation varies depending on the exact procedure, and may include fasting, bowel preparation, or a temporary pause on certain medications such as blood thinners. You will be given specific written instructions ahead of your appointment. Always mention any allergies, medications, or previous reactions to sedation when booking.

  • What happens during Virtual colonoscopy vs colonoscopy?

    A specialist examines or samples the relevant area using a thin scope or needle, often with local anaesthetic or light sedation to keep you comfortable. The procedure itself is usually relatively quick, though you may need to allow extra time for preparation and recovery. Staff will explain what to expect and answer any questions beforehand.

  • Does Virtual colonoscopy vs colonoscopy hurt or carry risks?

    You may experience mild discomfort, and biopsy or endoscopic procedures carry a small risk of complications such as bleeding or infection, which staff will discuss with you beforehand. Sedation or local anaesthetic is usually used to minimise discomfort. Any specific risks relevant to your situation will be explained as part of your consent process.

  • How long do results take?

    Results are usually reported by a specialist within a few days, though this can vary depending on the complexity of the test and whether further analysis is needed. You will normally be told when and how to expect your results at the time of booking. Urgent findings are typically flagged and communicated more quickly.

  • What do abnormal results mean, and what happens next?

    An abnormal result does not automatically mean something serious - it simply indicates that further assessment may be needed. Your doctor will review the findings in the context of your symptoms, history, and any other test results before recommending next steps, which might include further investigation, referral to a specialist, or reassurance that no action is needed. Always discuss your specific results with a doctor rather than interpreting them alone.

  • Is Virtual colonoscopy vs colonoscopy available privately, or should I wait for the NHS?

    Virtual colonoscopy vs colonoscopy can usually be arranged privately, often within days, with results reviewed by a specialist rather than waiting for routine NHS scheduling, which can take considerably longer depending on local demand. Cost varies by provider, and many private providers accept both self-referral and GP or specialist referral. Your GP can also advise on the appropriate NHS pathway if you would prefer to wait.

  • Is Virtual colonoscopy vs colonoscopy accurate and reliable?

    This is a well-established test used routinely in clinical practice, and when performed and interpreted by an experienced specialist it is generally considered reliable. As with any test, results are always interpreted alongside your symptoms and medical history rather than in isolation. Occasionally a test may need to be repeated or supplemented with further investigation for a fully clear picture.

  • How do I book Virtual colonoscopy vs colonoscopy privately, and how quickly can I be seen?

    You can typically book privately with or without a GP referral, and appointments are often available within a matter of days. A specialist reviews and reports the results, with a clear explanation of what they mean and any recommended next steps.