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Virtual colonoscopy (CT colonography)
virtual colonoscopy · CT colonography · CTC · CT scan of the colon
CT images of your large bowel. The bowel is gently inflated with air. No tube with a camera is used.
To look for polyps if a regular colonoscopy is not possible or could not be completed, or if your doctor decides.
⏱ Duration: usually 15 to 20 minutes in the room, plus bowel prep the day before; the report in 1 to 2 days
Be sure to tell your doctor
How to prepare
- 1 to 2 days before. A low-fiber diet: no vegetables, fruit, seeds, nuts, or beans. Ask the clinic for your plan.
- Bowel prep. The day before, you drink a bowel prep solution as your doctor says. A special contrast to mark stool is often added.
- On the day. Usually no food. Drink clear liquids as the clinic tells you.
- Medicines. Do not stop them on your own. Tell your doctor. They will decide.
What to bring
- Your referral
- Past colonoscopy reports
- A list of your medicines
How it goes
- You lie on your side
- A thin, soft tube is placed in your bottom
- Air or carbon dioxide is passed through it to open up the bowel
- Sometimes a medicine is given into a vein to relax the bowel
- Images are taken while you lie on your back and on your stomach. You need to hold your breath
- The tube is removed
What you'll feel
- Bloating and cramps while the gas is added
- It does not hurt, and the feelings pass quickly after the test
Afterwards
- You will pass gas over the next hour. This is normal
- You can eat as usual
- If polyps are found, your doctor usually sends you for a regular colonoscopy to remove them
Contact a doctor straight away if
- Severe belly pain, a hard belly, a fever, or bleeding from the bottom: call emergency services
Common questions
Can I skip the bowel prep?
No. Leftover stool can hide a polyp or look like one.
Does it replace a regular colonoscopy?
Not always. With CT, a polyp cannot be removed or sampled. Your doctor chooses.