Reliable and non-invasive, virtual colonoscopy is a tomography test (CT scan) that captures 3D images of the inside of the colon and rectum. Colonoscopy gives the radiologist a screen view of the intestinal wall and can accurately navigate through specific areas. It can also assess general abdominal structures. In 5 to 10% of cases, other significant medical conditions are noted (e.g. an ovarian cyst or diverticulitis).
The examination requires insufflation of CO2 (carbon dioxide) to distend the colon using a very small flexible rectal tube. Unless otherwise indicated, an intravenous injection of Hyoscine Butylbromide will be administered. The procedure usually takes 10 to 15 minutes.
Here are a few facts about colorectal cancer
- The third most common type of cancer in Canada, in both men and women
- One in 14 men and one in 15 women are at risk of colorectal cancer during their lifetime
- In Canada, colorectal cancer is the second leading cause of death by cancer
- The death rate after diagnosis is about 40%
- Almost 95 percent of cases occur after age 50
- More than half of cases are diagnosed in people age 70 or older
Remember that early detection can cure nine of every 10 people.
For the procedure, you will be asked to:
- Change into a hospital gown and remove your jewellery and all metal objects, which can interfere with image quality
- Lie comfortably on an examination table
During this time, the technologist will:
- Insert a small flexible tube into your rectum to inflate your colon. You may experience minor abdominal cramps that will quickly subside.
- Inject an intestinal relaxant (hyoscine hydrobromide) and take two series of images of 30 seconds each.
Depending on the test prescribed by your health professional, it may be required to inject a contrast agent. We will go through a list of contrast agents with you when you book your appointment. If you think you may be allergic, please let us know.
Preparing for the Examination (for adults)
A virtual colonoscopy requires full purging of the colon, so you must follow the steps below to prepare.
You can obtain all the following items at no charge from one of our clinics:
- One bottle (225 mL) of E-Z-Cat 4.6% barium oral solution (do not dilute the content)
- The preparation kit
- Three (3) bisacodyl (Dulcolax) tablets
- One bottle of ready-to-drink iodinated contrast material (Gastrografin 30 mL)
Two (2) days before the examination, please follow this modified diet to properly prepare:
First day of preparation
- Clear liquids only
- Clear broth
- White bread and white pasta
- One 125 g (4 oz.) serving of tuna or skinless white poultry per meal, or 2 eggs
- Tomato sauce without vegetables, peels or onions
- Margarine and oil
- Fibre-free liquid meal substitutes
- Fruit and vegetables
- Red meat
- Dairy products
- Any type of grain, cereal or whole wheat product
- For vegan patients (who do not consume any animal products), substitute chicken, tuna or other fish with tofu (not fried).
The day before the examination
The evening before the examination, it is important that you not eat any solid food.
- Drink at least 250 mL (8 oz.) of clear liquid (liquid meal replacements are permitted).
- In the morning, drink at least two (2) 250 mL (8 oz.) glasses of clear liquid. Avoid coffee and cola.
- Prepare the Bi-PegLyte solution as follows:
- Dissolve the entire contents of each 70 g pouch in 1 litre (32 oz.) of water.
- Stir until you get a clear solution. Do not add other ingredients (e.g. flavourings).
- Refrigerate the solution to improve the taste.
- Drink at least 250 ml (8 oz.) of clear liquid (liquid meal replacements are permitted).
- Drink half of the E-Z-Cat 4.6% barium oral solution.
- Take all three Dulcolax tablets orally without chewing.
- Apply petroleum jelly (Vaseline) to the anus to reduce irritation caused by diarrhea.
- Repeat as often as necessary during preparation.
- No later than 5:00 p.m., eat only clear liquids for supper (e.g. chicken broth, water).
- Drink the remaining E-Z-Cat 4.6% barium oral solution.
At 6:00 p.m., start drinking the Bi-PegLyte preparation. Follow the instructions on the package.
- Quickly drink one glass (240 mL) of previously prepared solution every 10 minutes.
- Be sure to drink all of the solution prepared with the first pouch.
- If necessary, pause for an hour or two between drinking the two litres of Bi-PegLyte preparation.
- Drink 250 to 500 mL of juice or other clear liquid to hydrate yourself, if necessary.
At 10 p.m., drink the bottle of Gastrografin (30 mL), unless you are allergic to iodine.
- If you are in doubt, call 514-866-6622.
- Then, drink one 250 mL (8 oz.) glass of clear liquid.
- Do not eat or drink until the examination is finished.
- If necessary, take your usual medication with a sip of water.
The morning of the examination
- No eating or drinking is permitted.
- Smoking and chewing gum are not permitted.
- If necessary, take your usual medication with a sip of water.
In the evening
Do not be concerned if you fail to have a bowel movement within six hours after taking the tablets. Six hours after taking Dulcolax or shortly after supper, start drinking the solution. Quickly drink one glass (240 mL) of the solution every 10 minutes. Be sure to drink all of the solution from the first pouch.
You can take a one- or two-hour break between drinking the two litres of Bi-PegLyte preparation. If you feel the need, you can drink 250 to 500 mL of juice or other clear liquid to hydrate yourself.
Mix the Gastrografin with the second litre of Bi-PegLyte preparation. REPEAT by drinking the second litre of the prepared solution (240 mL every 10 minutes).
- You will pass watery stools within one hour, and then soft stools one to two hours after you finish drinking the solution. The enema is finished when the fecal evacuation is colourless.
- Bloating or abdominal distension may occur before you pass the first stool. If abdominal distension or discomfort persists, temporarily stop drinking the Bi-PegLyte or drink each 240 mL serving at more widely spaced intervals (more than 10 minutes) until the symptoms disappear.
- If you experience severe swelling, abdominal pain or distension, slow down or temporarily stop taking the solution until the symptoms disappear. Report these symptoms to your doctor.
- You can take your usual medication with a sip of water.
A medical prescription is required to perform this examination.
Please note that CT-Scan examinations are not covered by the Régie de l’Assurance Maladie du Québec (RAMQ). However, most group insurance plans cover the costs.
If your healthcare professional has prescribed this examination or if you have any questions, contact us at 1 833 590-2715.