Virtual Colonoscopy vs Regular Colonoscopy

The American Cancer Society advises that men and women that are age 50 and above to begin screening for colon cancer for at least once every 10 years.

Early screening for colon cancer helps to prevent colon cancer. Noncancerous polyps in the colon can become cancerous over time if they are not removed on time.

What is Virtual Colonoscopy?

Virtual colonoscopy is a medical imaging procedure that uses CT scans to look for polyps or other growths inside your colon. The x-rays produce two and three-dimensional images of the entire colon and display them on a screen. The doctor views the entire colon on the screen and checks for any polyps or abnormal growths.

Virtual colonoscopy is a less invasive procedure and much safer than conventional colonoscopy.

What is Regular Colonoscopy?

Regular colonoscopy, also known as a conventional colonoscopy is the regular screening to detect for polyps or abnormal growths inside the colon. During a regular colonoscopy, a flexible tube (colonoscope) is inserted into the colon through the rectum. A tiny camera is attached to the tip of the tube for viewing the inside of the colon. The camera is connected to a screen with which the doctor views the inside of the colon for any available polyps or abnormal growths.

Which is better, a virtual colonoscopy or a regular colonoscopy?

Virtual colonoscopy is less invasive than regular colonoscopy. Virtual colonoscopy is also faster to perform. It does not require sedation and it is more comfortable. However, polyps found during a virtual colonoscopy can’t be removed. Polyps can be removed during a regular colonoscopy.

Let’s take a look at the pros and cons of each.

Pros of virtual colonoscopy

Less invasive

During a virtual colonoscopy, a short thin tube is inserted just into your rectum and your intestine is filled with air through the tube. It is less invasive than a regular colonoscopy.

Fewer complications

Complications during a virtual colonoscopy are fewer and milder as compared to regular colonoscopy. You won’t have to worry about bleeding or tearing of your colon.

More comprehensive

Apart from viewing the inside of your colon, your doctor can view the area outside your colon. It provides a more comprehensive view of your intestine and pelvis area.

It takes shorter time to perform

A virtual colonoscopy takes just about 10-15 minutes to be completed.

It is an alternative to regular colonoscopy

Virtual colonoscopy is an alternative to regular colonoscopy. Individuals that are not good candidates for regular colonoscopy can undergo virtual colonoscopy. Individuals that are on blood thinners can also undergo virtual colonoscopy.

No anesthesia

Virtual colonoscopy does not involve the use of anesthesia. It is more comfortable and without pains

Cons of virtual colonoscopy

Inability to remove polyps

If your doctor finds polyps or any abnormalities, they can’t be removed. You will need to undergo a regular colonoscopy so that the polyps or abnormalities found can be removed.

Radiation exposure

Virtual colonoscopy exposes you to a low dose of radiation during the CT scan.

Pros of regular colonoscopy

Polyp removal

During a regular colonoscopy, your doctor can remove polyps or abnormalities that are found.

Little discomfort

Your doctor will give you anesthesia to make you feel relaxed and comfortable during the exam.

Cons of regular colonoscopy


Complications of regular colonoscopy are more than virtual colonoscopy. Inserting the tube through the rectum down to the whole length of the colon can cause bleeding of the rectum and tear of the colon.

Longer time

Regular colonoscopy takes a longer time to be completed.


Virtual colonoscopy is more comfortable with fewer complications. It is less invasive and faster to perform. However, polyps can’t be removed if found, which is a serious drawback. You will then need to undergo a regular colonoscopy for the polyps to be removed.

Regular colonoscopy on the other hand may have more complications. Though it is more invasive, you will be given anesthesia to make you comfortable throughout the procedure. Any polyps found during the procedure can be removed.

Regular colonoscopy is better recommended than virtual colonoscopy because you won’t need to undergo another procedure to remove polyps if found. If polyps are found during virtual colonoscopy, you will still need to undergo a regular colonoscopy. It is best to undergo a regular colonoscopy to prevent undergoing another procedure.

How effective is a virtual colonoscopy?

Study showed that virtual colonoscopy is able to detect 90% of polyps of 10 millimeters or more in diameter. Virtual colonoscopy has the same accuracy as regular colonoscopy. However, regular colonoscopy is able to detect much smaller polyps (less than 5 millimeters) that virtual colonoscopy may not be able to detect.

How long does a virtual colonoscopy take?

It takes about 10-15 minutes for a virtual colonoscopy to be completed.

What is the prep for a virtual colonoscopy?

The prep for virtual colonoscopy is the same as the prep for regular colonoscopy.

  • You may need to follow a special diet for a few days before your procedure.
  • You may need to take your prep or laxatives to clean out your colon for easy viewing.
  • You may need to drink a special contrast liquid before the test so that your doctor can see the inside of your colon more clearly.
  • Inform your doctor about the medications you’re currently taking including supplements, herbal medications, and vitamins.
  • Inform your doctor if you have any allergy to the contrast dye liquid that will be used during the procedure.
  • Follow all other instructions that will be given to you by your doctor.

What can a colonoscopy show that a CT scan cannot?

Colonoscopy can show very small polyps of less than 5 millimeters that are not easily seen by CT scan. Very small polyps that are less than 5 millimeters may not be seen by a CT scan but can be seen by colonoscopy.

At what age is a colonoscopy no longer needed?

Individuals that are older than age 75 and have been undergoing regular colon cancer screening since age 50 without any polyps or abnormalities found and are not at increased risk of colon cancer may not need to continue routine colonoscopy.

Can virtual colonoscopy detect Crohn’s?

Virtual colonoscopy cannot accurately diagnose Crohn’s disease or other inflammatory bowel diseases. It is not recommended to be used to check for Crohn’s disease.

However, virtual colonoscopy can detect thickened bowel wall and deep ulcers in patients with Crohn’s disease.

Why have a colonoscopy after a CT scan?

A CT scan can detect for the presence of polyps but the polyps can’t be removed. You will need to undergo a colonoscopy after a CT scan to remove polyps.

How long does it take to get results from a CT colonoscopy?

The results from a CT colonoscopy may be available within 2 days or more. Check with your doctor to know the exact time that your results will be available.

Is there an alternative to having a colonoscopy?

Colonoscopy is a common method of screening for colorectal cancer. There are other effective alternatives for screening for colon cancer. These include


Sigmoidoscopy is similar to a colonoscopy but does not check the whole of the colon. It checks only a smaller portion of the large intestine. The preparations for a sigmoidoscopy are similar to preparations for a colonoscopy. It is typically less expensive and with fewer risks than colonoscopy.

CT or virtual colonoscopy

CT or virtual colonoscopy is a medical imaging procedure that uses CT scans to search for polyps or abnormalities inside your colon

Fecal immunochemical testing (FIT)

This involves analyzing stool samples. It uses antibodies to detect traces of blood in a stool sample. Traces of blood indicate that there is bleeding or abnormalities in the gastrointestinal tract.

Fecal occult blood testing

This also involves analyzing stool samples. Traces of blood in the stool may indicate abnormalities in the gastrointestinal tract.

Stool DNA

Stool DNA involves analyzing a stool sample to check for blood and specific DNA. A doctor may use stool DNA in combination with FIT.

What are the risks of a colonoscopy?

The risks of a colonoscopy include:

  • Tiny tears in the rectum wall or colon
  • Bleeding
  • Adverse reaction to anesthetic or constraint dye
  • Infection

Virtual Colonoscopy vs Regular Colonoscopy

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