Virtual Colonoscopy (CT)

A virtual colonoscopy by computerized tomography (CT scan) facilitates the examination of the large intestine. The images produced during this exam facilitate the diagnosis of colorectal polyps, as well as colon cancer.

The virtual colonoscopy is part of the services offered by the Medical Imaging Department.

How to access our services?

You need to have a referral from your physician in order to schedule an appointment for this exam.

About The Program

Before your appointment

  1. Your family physician must send us a requisition by fax. Please ensure your contact information is up to date so we can call you.
  2. Our office will contact you in approximately 2 to 4 weeks after we received the referral from your physician. Your appointment will be scheduled between one and two weeks later. Your appointment will take place approximately 6 weeks after the reception of the referral from your physician.
  3. At least three days before the exam, you must come to the hospital to pick up a product and instructions to prepare for the exam.
  4. A few days before the exam, we will call you to remind you of your appointment.

What to bring

  • Health card

Exam preparation

Preparation for a colonoscopy includes several steps carried out over two days. How well you prepare will have a direct impact on the quality of your exam. We ask that you follow the instructions you are given in order to receive the most precise results possible.

At least three days before the exam

Purchase these products at the pharmacy:

  • GoLYTELY (or Colyte or Peglyte)
  • Laxatives: 6 tablets of 5 mg of Bisacodyl

Visit the hospital to pick up these products:

  • Readi-Cat (1 bottle)
  • Preparation sheet with instructions
  • Please pick up the Readi-Cat at the CT scan appointment office on weekdays, between 7:30 a.m. and 3:30 p.m.

Two days before the exam

  • You must follow a special diet for two days. The goal of this diet is to eliminate fiber, fat and solid content from your intestines.
  • During this period of preparation you must drink at least one glass (240 ml) of water or clear liquid every hour.

Clear liquids permitted

  • Water
  • Fruit juice without pulp (apple, orange, lemonade or white grape)
  • Clear soft drinks (7UP, Sprite)
  • Gatorade or similar products

Food and products to avoid

  • Dairy products
  • Alcohol
  • Fruits and vegetables
  • Tomato and prune juices
  • Butter and other fatty products such as cream, margarine, canola oil and olive oil

Foods you can eat

  • Boiled or poached eggs
  • White bread without butter or margarine
  • Skinless turkey or chicken, cooked without fat
  • Fish cooked without fat
  • Boiled potatoes without skin
  • White rice
  • White pasta
  • All items included in the Clear liquids list

The day before the exam

  • You cannot eat solid foods the day before the exam. You must follow a liquid-only diet to ensure your intestines are empty.
  • You must drink at least one glass of water each hour until night time.

Liquid diet

  • Clear broth or consommé
  • Ensure or similar product without fiber, vanilla flavoured only
  • Jello
  • Popsicle
  • Tea or coffee without milk or cream – sugar and honey are permitted


  • Take ¼ of the bottle of Readi-Cat
  • Item(s) from the liquid diet menu (your choice)
  • Prepare the GoLYTELY mixtures according to the directions on the package and place in refrigerator.


  • Take 4 tablets of Bisacodyl 5 mg laxatives.
  • If you feel very ill after taking the laxative, do not take any more. Please consult your physician or visit the HGH emergency department.
  • Take ¼ of the bottle of Readi-Cat.
  • Item(s) from the liquid diet menu (your choice).

At 5:00 p.m.

  • Drink 2 litres of GoLYTELY, taking one glass every 10 minutes.
  • Your stools should be liquid and clear or light yellow in colour. If not, continue to drink the GoLYTELY until your stools are liquid and clear or light yellow.


  • Take ¼ of the bottle of Readi-Cat
  • Item(s) from the liquid diet menu (your choice).

At 10:00 p.m.

  • Take 2 tablets of Bisacodyl 5 mg laxatives

From midnight on

  • Nothing more to eat or drink prior to the exam.

The morning of the exam

  • Do not eat or drink.
  • If there are medications you need to take, you can do so with a small bit of water.
  • Bring a snack to eat after the exam.

When you arrive

  • Please register at the self-service registration kiosk 30 minutes before your scheduled appointment.
  • After registration, please report directly to the Diagnostic Imaging receptionist who will give you directions to the room for your test.
  • Depending on the type of examination, you may need to remove your clothes and wear a hospital gown.
  • You will have to remove your jewellery, piercings, glasses and any metal objects.

Exam process

  • During the exam, you will be lying down on a table.
  • A muscle relaxant will be injected to prevent intestinal spasms.
  • Next, a tube will be inserted into the rectum and gas will be used to fill the intestine. This gas allows images to be taken by the CT scanner.
  • Images are taken while you are lying down on your back and on your stomach. Sometimes images are also taken while you lie on your side.
  • Some people experience cramping or bloating during the exam or up to 30 minutes after the exam.
    The exam lasts about 30 minutes.
  • You can resume your normal eating habits right after the exam.
  • You will be able to drive your vehicle after the exam, but it is preferable that you arrange for a ride home.

Test results

  • Radiology technologists are not able to give you the results of your exam. Results will be sent to your physician within 10 working days.
  • The physician who referred you for the exam will give you your results; therefore, you will need to schedule an appointment with this physician.