Virtual CT Scan Colonoscopy

One day before your scan, you’ll begin preparing. Starting 24 hours before your scan, here’s what you’ll need to do:

• Don’t eat any solid food.
• Drink only clear liquids for all meals. Clear liquids include Gatorade, water, coffee or tea (no milk), ginger ale, apple juice, broth, popsicles and Jell-O.
• Start taking Dulcolax to induce bowel movements. Your doctor will provide specific instructions for taking Dulcolax. Here are general guidelines you will need to follow (times may change depending on the time for your scan):
  • Take two Dulcolax tablets at 10 a.m. 
  • At 4 p.m., mix an entire bottle of Miralax (238g) with 64 oz. of Gatorade until completely dissolved. 
  • Drink an 8 oz. glass of the Miralax/Gatorade mixture every 10 to 15 minutes until the solution is gone. The solution will cause you to have repeated loose stools (diarrhea), which is the expected result. It typically works within 30 minutes but may take up to three hours to have an effect.   
  • Take 2 more Dulcolax tablets at 10 p.m. Continue to drink plenty of clear liquids. 
  • Don’t exceed the recommended Miralax/Dulcolax doses. Doing so can cause serious side effects.

Don’t eat after midnight the day before your exam. You should take your regular medications with water, unless instructed by your doctor. If your scan is scheduled for the afternoon, you may have clear liquids until 10 a.m. 

If you are diabetic, take half your usual dose of insulin on the morning of the procedure. If you take a “diabetic pill,” you may skip it the morning of the procedure unless instructed otherwise. If you have any other questions regarding your medications, please contact your primary care provider.

Please arrive 15 minutes before your appointment time. Wear comfortable, loose-fitting clothes for your scan. Bring a list of all medications and allergies so we can make a copy for your record.

The technologist performing your scan will greet you and escort you to the exam room. There, you may be asked to change into a hospital gown.

The technologist will position you on the table lying on your back or side. They will insert a small, flexible tube into your rectum. A radiologist will then gently pump air into the colon. This helps “smooth out” the colon by temporarily eliminating folds or wrinkles and helps the doctor view the colon.

After the air is inserted, you’ll be asked to roll onto your back. The CT table will move you in and out of the scanner. While in the scanner, you will hear slight buzzing, clicking and whirring sounds. This is the sound of the scanner working. You may then be asked to lie on your stomach for more images.

Scans usually last 15 to 20 minutes.

There are no restrictions following this test. You may return to your regular diet and activities after the scan is complete. Your doctor will receive your results a few days after your scan. They will share the results with you and discuss next steps.