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What is Virtual Colonoscopy?
A CT Colonoscopy scan uses x-rays and a computer to construct cross-sectional images or “slice” pictures of your bowel (colon) in great detail. Imagine your body as a sliced loaf of bread .You would then be able to take out individual slices to view the internal structures as well as producing three dimensional images of your body.
Risks and benefits:
All medical procedures carry some risks. One of the risks of this procedure is radiation. The equipment used is modern and is subject to regular maintenance and on-going quality assurance checks. Radiation doses are kept as low as possible. There is also a very small risk that the examination may cause a small hole in your bowel (a perforation). The risk is very low (approx. 1 in 3000 tests). When it happens, most cases resolve without treatment but it may require hospital admission and observation under the care of a surgeon. We always weigh any risks against the benefits that may be gained from any procedure before going ahead. Your Doctor and our Radiology team will have agreed that the benefits to you will outweigh any risk of having this procedure. If you have any questions or do not wish to proceed please contact us as soon as possible.
If you have in the past had any x-ray procedure where you were injected with contrast and had a reaction or if you are allergic to Iodine please inform the radiographer when you arrive. For these examinations, you will be required to take Picolax® , a strong laxative. If you are taking oral medication such as contraceptives, antibiotics or anti- epileptics, please note that their effects may be modified.
Female patients 12-50 years of age or if you are having menstrual cycles:
You must notify the department if:
• This appointment is not within 10 days of the start of your last period
• There is a possibility that you may be pregnant
If either of these applies, a new appointment will be made.
Patients with diabetes:
It may be necessary to make adjustments to the dietary instructions in the leaflet. Please contact your Diabetes Nurse Specialist or Practice Nurse.
Do I need special preparation?
It is important for this examination that your bowel is as empty as possible. Please follow the suggested diet and take the Picolax® as directed. You are only allowed to eat certain foods as these will not interfere with the bowel preparation. Please disregard the dietary instructions from the Picolax® leaflet and only refer to this leaflet.
List of foods that you may have:
• Cornflakes, Rice Krispies or Special K with Coffee-Mate made up with water
• Boiled or poached eggs
• Boiled or mashed potatoes (do not add milk or butter)
• Plain white pasta or noodles
• Plain boiled white rice
• Chicken, fish or shellfish
• Gravy – using stock cubes made with water only
• White bread/toast without dairy products
• White or brown sugar or sweeteners
• Clear jelly
• Clear soups or broth
Two days before your examination
Do not eat any of the following: high fibre cereals, bran, fruit, vegetables or red meat.
Take all medicines as normal, with the exception of codeine, iron tablets, Lomotil and other stomach medicines
The day before your examination (8am):
You have been sent two sachets of Picolax®. Dissolve the contents of one sachet in a large cup of water, stirring well. The solution may become hot. Wait until it cools before you drink it. This can take effect quickly. Be prepared for frequent bowel movements. You are advised to stay at home if possible or somewhere you can have access to a toilet without embarrassment.
You must drink plenty of clear fluids:
Drink at least one full glass of clear fluid every hour from 8am until 9pm. Suggested clear fluids: water, mineral water, lemon/herbal/fruit teas, black coffee or tea, Bovril Marmite or Oxo, fruit squash.
You may use this table to keep check of the times of fluid intake
8am – 9am Breakfast
• Either one boiled or poached egg or cereal
• One slice of white bread with low fat spread, honey or seedless jam
• Tea or coffee: black or with Coffee Mate – do not have milk
Midday – 2pm Lunch
• Small portion (about 4oz/100g) of steamed, poached or grilled (not fried) white fish, chicken or soya/quorn
• 2oz/50g white pasta or rice; or a small portion of boiled potato or white bread without butter
• No fruit or vegetables
• Clear jelly for dessert
Take the second sachet of Picolax® following the same instructions as before.
6pm – 8pm Evening meal
• No solid food
• Clear soup or Bovril or marmite drink
• Black tea or coffee, no milk or substitute
• Clear jelly
The day of your examination:
No food until after your examination. You may continue to drink clear fluids until 2 hours before your appointment time
2 hours before your scan appointment
• Mix the contents of the 50ml Gastromiro bottle with 500ml of cold water. Drink this over the next 40 minutes.
Do Not Take Gastromiro if you:
• Are ALLERGIC to iodine
• Have Hyperthyroidism
• Suffer from regular choking/coughing episodes when drinking fluids (this is a condition called aspiration)
• Have a medical condition known as bronchooesophageal fistula (a join between your windpipe and gullet)
• Have been treated with interleukin-2
• Have been diagnosed with a fluid/electrolyte imbalance
You may bring a snack (e.g. biscuits) to eat straight after your examination.
What happens when I arrive?
On attendance you will be checked in by the reception team and asked to wait in our waiting area. At the allotted time, you will be asked to remove all your clothes except your shoes and put on
an x-ray gown. You may bring a dressing gown if you wish. You may also bring slippers to wear instead of shoes. You will then be called into the scanning room at your appointment time. The
procedure will be explained to you and we will check for any allergies. The procedure may take up to half an hour and you may be asked to wait for up to 30 minutes afterwards.
How is the CT Virtual Colonoscopy performed?
• You will be asked to lay on the scanner table
• A small needle will be inserted into a vein usually in your arm
• A soft tube will be placed into your back passage (rectum) to introduce a small amount of gas
• A bowel relaxant may be injected through the needle in your arm. This reduces any bowel cramping and allows the bowel to expand. This injection can cause blurred vision for about 20 minutes.
• A tube will be attached to the needle in your arm and contrast dye will be injected, this is to highlight the blood vessels around your bowel.
• You will then be moved into the scanner
• The table will move in and out of the scanner as the x-rays are taken. If you have the needle in your arm, the contrast dye is injected as the pictures are taken.
• It is important that you follow instructions closely and stay as still as possible during the filming sequences.
Will it be painful?
The insertion of the needle into the vein may cause discomfort to some people but this is the same as for any routine blood test. The remainder of the examination is painless. You may experience mild abdominal discomfort like trapped wind, but it should be no worse. If you are having more discomfort than this please inform the radiographer.
After the examination:
You may resume normal activities. Please ensure your vision has returned to normal if you intend to drive home. In the rare event that after the examination you develop painful blurred vision you must attend hospital (A&E) for assessment. Please be aware that you may still have loose stools for a couple of days after your scan but this will return to normal when you eat and drink normally.
How do I find out the results?
If you were sent by a Consultant from the hospital, he or she should contact you regarding results.
If you have had the x-ray dye injection:
Although extremely rare, some people have a delayed allergic reaction to the contrast. If this happens and you have not left the hospital, you should let someone in the department know. If you have left the hospital, you should contact your GP.
If you cannot contact your doctor, phone the Radiology department between 9-00am – 5-00pm Monday to Friday. At all other times come to the A&E department of the hospital.