What is virtual colonoscopy?

Virtual colonoscopy is a procedure used to look for signs of pre-cancerous growths, called polyps; cancer; and other diseases of the large intestine. Images of the large intestine are taken using computerized tomography (CaT Scan). A computer puts the images together to create an animated, three-dimensional view of the inside of the large intestine.

How is a virtual colonoscopy performed?

For the exam, a small tip is inserted about two inches into the rectum to gently inflate the colon with air for optimum visualization. The CT images are then quickly obtained while the patient lies comfortably on his or her back. Then repeat scanning is done with the patient lying on his or her stomach. The resulting images are computer reconstructed to provide views of the entire inside of the colon in two positions. During the exam you will be alone in the examining room however, a technologist and nurse in the adjacent control room can see and hear you, and you can speak to them at any time.

How do I prepare for my virtual colonoscopy exam?

Your test will be performed at the Radiology CT Scan at either Abington Memorial Hospital (telephone # 215-481-4284) or Lansdale Hospital (telephone # 215-361-4470).

Prior to the exam a patient undergoes a bowel prep and special diet to cleanse the colon. Adherence to this special diet and a bowel preparation is very important to insure that the colon is adequately cleansed for more accurate assessment.

How do I prepare for my virtual colonoscopy exam?

  • On the day of your exam, wear comfortable, loose-fitting clothing.
  • Avoid clothing with zippers and snaps as metal objects can affect the image.
  • Depending on the part of the body that is being scanned, you may also be asked to remove hair pins, jewelry, eyeglasses, hearing aids and any dentures.
  • You may be asked not to eat or drink anything for one or more hours before the exam.
  • Women should inform their doctor or x-ray tech if there is any possibility that they are pregnant.
Doctor holding colonoscopy equipment in his hands before starting a procedure

Prep for CT Colonography

A bowel preparation prescribed by your primary doctor will be needed.

Patient will need to pick up at AMH CT Department

  • Tagitol V package (package contains three 30 milliliter bottles)

ONE Day before your colonography

  • Liquids for the entire day – no solid food until after the procedure is completed! Suitable liquids include broth, apple juice, Gatorade, ginger ale and other sodas, black coffee or tea, jello, ice pops, white cranberry juice.
  • Drink as much fluid as possible, including juice and broth. Don’t just drink water
  • At what would be your normal breakfast time, drink one bottle of Tagitol.
  • At what would be your normal lunch time, drink one bottle of Tagitol.
  • At what would be your normal dinner time, drink one bottle of Tagitol.
  • Take bowl prep as prescribed by your primary doctor

Once you have completed the prep, resume clear liquids. If your procedure is before 1 pm stop drinking liquids at midnight. If your procedure is 1 pm or later you may drink liquids until 8 AM. If you are unable to finish the preparation, please wait one hour and try your best to finish the preparation.

Day of your CT colonography

You may take your necessary morning medications with a sip of water (no more than 2 tablespoons)


  • DIABETES: If you take medications for diabetes or to control your blood sugar, call your primary physician for instructions on how to take these medications on the day before your colonography and on the day of the procedure.

If a polyp is suspected on this test, please call your doctor to discuss the results and decide on further management.

The day of the exam – Do not eat or drink anything from midnight until the exam is complete.  However, you may take your regular medications as directed with small sips of water.

Please call if you have any questions about the preparation or your exam.

Other important information

  • The vast majority of patients who have VC report a feeling of fullness when the colon is inflated with air, as if they need to pass gas. The amount of cramping felt varies with patients but most find this minimal.
  • Since sedation is not required, patients are free to leave the CT suite immediately following the exam without the need for prolonged observation or recovery. Patients can resume normal activities immediately after the procedure and can eat, work or drive without delay.
  • Because this is an x-ray test it should not be performed if the patient is pregnant.

How will I get my results?

After your scan is completed, the images are reconstituted with special computer software to provide views of the inside of the colon. The study is then interpreted by our radiologists. A full report of the findings is forwarded to your referring physician, who will discuss findings and any recommendations with you.