Is virtual colonoscopy as good as colonoscopy?


Colon cancer screening is essential for early detection and prevention. Virtual colonoscopy, also known as CT colonography, is an advanced imaging procedure that provides an alternative to traditional colonoscopy. This method utilizes computed tomography (CT) technology to produce detailed images of the colon and rectum, allowing gastroenterologists to examine for polyps or other abnormalities without inserting a scope into the colon.

Is a Virtual Colonoscopy Painful?

Unlike conventional colonoscopies, virtual colonoscopies are generally less painful. There is no sedation required, and the procedure involves only the insertion of a small tube into the rectum to inflate the colon with air. Some patients may experience minor discomfort or pressure due to the air inflation, but painful sensations are rare.

Cost of Virtual Colonoscopy

The cost of a virtual colonoscopy can vary depending on geographical location, healthcare facility, and insurance coverage. Generally, it is less costly than a traditional colonoscopy due to the lack of anesthesia and shorter procedure time. Patients are advised to consult with their insurance provider to understand the coverage details and potential out-of-pocket costs.

Preparation for a Virtual Colonoscopy

Preparation for a virtual colonoscopy is similar to that of a traditional colonoscopy. Patients must follow a clear liquid diet for 24 hours before the procedure and take a bowel-cleansing laxative. The goal is to ensure the colon is free of solid waste, which enhances the clarity and effectiveness of the images produced.

Virtual Colonoscopy vs. CT Colonography

Virtual colonoscopy and CT colonography are terms often used interchangeably. Both involve the use of CT scanning to obtain cross-sectional images of the abdominal organs, specifically focusing on the colon. The terminology may vary, but the procedure, methodology, and purpose remain consistent across both terms.

Side Effects of Virtual Colonoscopy

Virtual colonoscopy is considered a safe procedure with a low risk of complications. The most common side effect is discomfort due to the air introduced into the colon. Rarely, there is a risk of bowel perforation, but this is significantly lower than with traditional colonoscopy.

Radiological Insights in Virtual Colonoscopy

Radiology plays a crucial role in virtual colonoscopies, as radiologists specialize in interpreting the images obtained during the procedure. They assess for polyps, cancers, and other abnormalities that might require further investigation or intervention. The detailed imaging allows for a comprehensive view of the colon, aiding in accurate diagnoses.

Advantages of Virtual Colonoscopy

Virtual colonoscopy provides several benefits:

  • Non-invasive Nature: Unlike traditional colonoscopy, virtual colonoscopy does not require sedation or the insertion of a colonoscope. This makes it less invasive and reduces the risk of complications such as perforation of the colon.
  • Convenience: The procedure typically takes about 10-15 minutes, with no need for sedation, so patients can return to their daily activities immediately.
  • Broad Reach: It can visualize more of the colon than a traditional scope, sometimes providing a view of areas that might be difficult to reach due to tight turns or obstructions in the colon.

Limitations of Virtual Colonoscopy

However, virtual colonoscopy also has some drawbacks:

  • Less Thorough for Small Polyps: It may not detect very small polyps as effectively as a traditional colonoscopy.
  • No Immediate Intervention: If a polyp or abnormality is found, a traditional colonoscopy may still be necessary to remove the polyp or perform a biopsy, which means undergoing another procedure.
  • Radiation Exposure: It involves exposure to radiation since it uses CT technology, which may be a concern for some patients.

Effectiveness and Suitability

In terms of effectiveness, studies have shown that for detecting significant polyps and cancers, virtual colonoscopy can be as effective as traditional colonoscopy. It is particularly effective for detecting polyps larger than 5 mm. The American Cancer Society recognizes both procedures as viable screening tests for colorectal cancer.

Ideal Candidates for Virtual Colonoscopy

Virtual colonoscopy is especially suited for patients who:

  • Are at average risk of colon cancer (with no symptoms and no family history of colon cancer)
  • Have health issues that make sedation risky
  • Prefer a less invasive option that does not require sedation

Recommendations by Dr. Christos Zavos

Dr. Christos Zavos recommends considering both the patient’s medical history and personal preferences when deciding between virtual and traditional colonoscopy. For those seeking further advice or who have specific concerns about their risk factors for colorectal cancer, consulting directly with a specialist such as Dr. Zavos can provide tailored guidance. Interested individuals can contact Dr. Zavos through, call at (+30)-6976596988 or (+30)-2311283833, or email for a comprehensive evaluation and to discuss the most appropriate screening method based on their individual health profile.

Last update: 25 April 2024, 21:35


Gastroenterologist - Hepatologist, Thessaloniki

PhD at Medical School, Aristotle University of Thessaloniki, Greece

PGDip at Universitair Medisch Centrum Utrecht, The Netherlands

Ex President, Hellenic H. pylori & Microbiota Study Group