CT Pneumocolon (Virtual Colonoscopy) Preparation – Patient Information

What is a CT Pneumocolon?

CT Pneumocolon (sometimes known as virtual colonoscopy) is an examination to primarily investigate the large bowel (colon). This is the area from the rectum to the appendix. The bowel must be clear for this procedure.

The tip of a soft rubber tube will be placed in the rectum through which gas will be introduced to distend the bowel enabling a clear view of the bowel
wall. The procedure should not be painful but may cause a little discomfort.

A contrast media (X-ray dye) and Buscopan (relaxes the colon muscles) may be administered intravenously into a vein in the arm during the examination. This will help to highlight the areas of interest.

Usually two scans are taken, one supine (lying on your back) and one prone (lying on your front). The examination may take up to one hour.

It is very important to read all the following instructions to empty your large bowel before the scan. The closer you can follow the instruction then the more accurate the test will be.

You will need to stay close to a toilet the day before the examination at all times as the Gastrografin is a laxative which can be extremely effective.

You will have received or picked up a bottle of Gastrografin to take as outlined in this information booklet. In your package you will also have received a pair of incontinence pants. These are for your own use on the way to the Imaging department when you have your scan as the drink can have a laxative effect. Some patients also find the use of baby wipes beneficial.

Do not take Gastrografin if you are allergic to iodine or if you have difficulty swallowing. Instead please contact the Imaging department.

If you are taking iron tablets stop taking them seven days before your scan.

Preparing for your CT Pneumocolon

Two days before your scan

You can eat low fibre foods including the following:
• Milk (two cups per day), plain yoghurt, cheese, butter, margarine
• White fish or chicken: boiled, steamed or grilled
• Eggs, tofu
• White pasta, white rice
• White bread, white pitta bread, white flour chapattis
• Potatoes with no skin e.g. mashed, boiled, chipped
• Smooth soups (no solid bits e.g. sieved chicken noodle, tomato), Bovril, Oxo
• Clear jelly, boiled sweets, ice cream, chocolate (no fruit or nut pieces)
• Salt, pepper, sugar, sweeteners and honey

Do not eat high fibre foods including the following:
• Red meats, pink fish (e.g. salmon)
• Fruit, vegetables, salad, mushrooms, sweetcorn
• Cereals, nuts, seeds, pips, bran, beans, lentils
• Brown bread, brown or wild rice, brown pasta
• Pickles, chutneys

Have plenty to drink from tea, coffee, squash, fizzy drinks, water, clear fruit juices (e.g. apple, grape, cranberry)

Suggested meals could include for example:
Breakfast: White bread/toast with butter and honey
Boiled or poached egg
Lunch: Grilled fish or chicken with white rice and boiled potatoes (no skin) or scrambled eggs on white toast, vanilla ice cream

After lunch do not any more solid food until after your scan. You can still have smooth soups (e.g. sieved chicken noodle soup, tomato, and vegetable bouillon), jelly, ice cream, Ambrosia custard, Complan drinks, Bovril and Oxo drinks, and water, clear juices, fizzy drinks, coffee and tea.

At 7pm: Drink half the bottle of Gastrografin (50mls). This is best done by mixing it with up to 400mls water and some cordial e.g. blackcurrant squash or a flavour of your choice works well.

The day before your scan

Do not each any more solid food.

You can still have smooth soups (e.g. sieved chicken noodle soup, tomato, vegetable Bouillon), jelly, ice cream, Ambrosia custard, Complan drinks, Bovril and Oxo drinks, and water, clear juices, fizzy drinks, coffee and tea.

Drink as much tea or water as you like, but drink at least ¼ pint (150mls) of fluid every hour during the daytime.

At 7pm: Drink the second half of the bottle of Gastrografin (50mls) This is best done by mixing it with up to 400mls water and some cordial eg blackcurrant squash or a flavour of your choice works well.

On the morning of your scan

Do not eat any solid food. You may drink water or clear sugary drinks.

On the way into the Imaging department please use the incontinence pants provided if you would prefer. Patients also commonly prefer to wear loose fitting/comfortable clothing for the journey. After the examination you can eat normally when you have left the department.

For female patients
If there is any chance of being pregnant, please notify the Imaging department before your scan. If you take oral contraceptives the diarrhoea may reduce their effectiveness. Continue taking oral contraceptives but use other precautions for the remainder of that cycle.

Contact us
Please contact the Imaging team about any general concerns on 0207 467 4317. Please also see the CT Pneumocolon patient information webpage