Colonoscopy vs Virtual Colonoscopy CT Colonoscopy 1

The differences between colonoscopy and virtual colonoscopy (CT Colonoscopy)

Colonoscopies are one of the most frequently recommended life-saving medical tests. Men and women at average risk for colon cancer should begin colorectal cancer screening at age 50. African American men and women should begin screening exams at age 45.

Many people choose a colonoscopy, the gold standard for colorectal cancer screening and prevention. But there’s another option: virtual colonoscopy.


A colonoscopy (koe-lun-OS-kuh-pee) is an exam used to detect changes or abnormalities in the large intestine (colon) and rectum.

During a colonoscopy, a long, flexible tube (colonoscope) is inserted into the rectum. A tiny video camera at the tip of the tube allows the doctor to view the inside of the entire colon.

If necessary, polyps or other types of abnormal tissue can be removed through the scope during a colonoscopy. Polyps are small growths on your colon wall. Left untreated, they can grow larger and develop into cancer over time. Tissue samples (biopsies) can be taken during a colonoscopy as well.

The benefits of a colonoscopy are: 

  • Being able to remove polyps immediately
  • Sedatives available to relieve discomfort

A colonoscopy poses few risks. Rarely, complications of a colonoscopy may include:

  • Adverse reaction to the sedative used during the exam
  • Bleeding from the site where a tissue sample (biopsy) was taken or a polyp or other abnormal tissue was removed
  • A tear in the colon or rectum wall

After discussing the risks of colonoscopy with you, your doctor will ask you to sign a consent form authorizing the procedure. 

Virtual Colonoscopy

During a virtual colonoscopy, your doctor does a CT (computerized tomography)  scan of your abdomen and pelvis to create 3-D images. These images show polyps and other abnormalities inside your colon and rectum. CT scans use radiation and sometimes contrast materials to help improve the quality of the images being produced. Both radiation and contrast dyes can cause side effects related to CT scans

The benefits of a virtual colonoscopy include: 

  • Less invasive — Your doctor will insert a tube in your rectum and colon that is shorter than the tube used for a colonoscopy
  • Fewer complications — You won’t have to worry as much about bleeding or tearing of the colon
  • More comprehensive — Your doctor can see the area outside the colon. This makes it possible to spot other problems in the pelvis area

Virtual colonoscopies can fall short to traditional colonoscopies in that they:

  • May require a follow-up colonoscopy — If your doctor sees a polyp or anything else unusual during your virtual colonoscopy, you’ll need to get a traditional colonoscopy to remove the polyp or perform a biopsy. This will be an additional test that your insurer will consider a diagnostic test, not a screening exam.
  • Have radiation exposure — Virtual colonoscopy exposes you to a low dose of radiation. You’ll be exposed to more radiation than a chest X-ray, but far less than a regular CT scan.


Both tests require a clean colon. That means you have to stick to a pre-op diet and can only have clear liquids the day before the test. You will probably also have to take some laxative solution to clear out your system.

No screening exam is 100% accurate. Your doctor may not find every polyp during your exam. That’s especially true for polyps that are harder to spot, like small or flat polyps. But, research shows that both exams are good options to check for and prevent colorectal cancer. Cost and coverage for screening exams varies. Before scheduling an exam, ask your insurance company if the exam is covered.

To book a scan, visit us at Medmo helps people schedule radiology imaging tests – such as MRI, CT scans, PET, and more – at nearby accredited centers and identify the payment solution that works best for them.


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