Colonoscopy vs. virtual colonoscopy: Get the facts

Men and women at average risk for colorectal cancer should begin colorectal cancer screening at age 45.

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

Colonoscopy: recommended every 10 years

During a colonoscopy, your doctor will use a flexible tube to insert a tiny camera into your colon through your rectum. They will look for polyps or other problems as the tube is withdrawn.

Polyps are small growths on your colon wall. Left untreated, they can grow larger and develop into cancer over time.

Pros

• Polyp removal — Your doctor can remove polyps during a colonoscopy. Polyp removal is the best way to prevent colorectal cancer.
• Little discomfort — You doctor can give you medication to help you stay relaxed and comfortable during the exam.

Cons

• Complications — It’s not common, but inserting the scope can cause bleeding and tearing of the colon.

Virtual colonoscopy: recommended every five years

During a virtual colonoscopy, your doctor does a CT scan of your abdomen and pelvis to create 3-D images. These images show polyps and other abnormalities inside your colon and rectum.

Pros

• Less invasive — Your doctor will insert a tube in your rectum and colon. But, it’ll be 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.

Cons

• 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 diagnositic test, not a screening exam.
• 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.

No test is perfect

If you’re leaning toward a virtual colonoscopy so you can avoid the colon-cleansing prep, think again. Both tests require a clean colon. That means you can only have clear liquids the day before the test, and you will have to take lots of laxative solution.

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.

“Colorectal cancer screening is so important because it saves lives,” says Robert Bresalier, M.D., professor of Gastroenterology, Hepatology and Nutrition at MD Anderson. “The most common symptom of colon cancer is no symptom at all. Screening allows us to detect it.”  

Start the colorectal screening discussion at your next check-up. If you’re at increased risk for colorectal cancer, talk to your doctor to see when you need to be screened. No matter what you choose, don’t put off this test for fear of discomfort. Either virtual or traditional colonoscopy can work for you if you follow your doctor’s recommended screening schedule and colonoscopy preparation.