Virtual Colonoscopy - Memorial Sloan-Kettering Cancer Center

PATIENT INFORMATION
FACT CARD
Virtual Colonoscopy
Introduction
A virtual colonoscopy is a new way of doing an exam of the large intestine (colon). It uses a CT scan plus a
computer. The computer creates pictures of the colon. The pictures are similar to what the doctor would see on
a standard colonoscopy. With the standard way of doing it, the doctor guides a thin flexible tube through the
colon. The doctor can also take small samples of tissue for testing or remove polyps. This can’t be done with a
virtual colonoscopy.
Preparation
ou will need to clean your bowel before the procedure. To do this, you will use the HalfLytely ® Bowel Prep Kit.
Follow our instructions. Do not follow the instructions on the HalfLytely box. Do not take other laxatives or more
than the dosage given below. Serious side effects can occur.
Two days before your procedure:
• Buy the HalfLytely ® Bowel Prep Kit at any pharmacy. Your doctor will give you a prescription. The kit has:
– One 5-mg tablet of bisacodyl
– HalfLytely powder in a 64-oz bottle plus flavor packets (lemon-lime, orange, cherry)
One Day before your procedure:
• Do not eat any solid food for the entire day before your procedure. Start the clear liquid diet. Drink a minimum
of one 8-ounce glass every hour after you get up. Have only clear liquids.
• Do not drink anything that is red or purple in color.
• Limit caffeinated beverages to two cups. Do not drink alcohol.
• Do not drink diet liquids, even if you are a diabetic. You will become weak and dizzy if you just drink water or
low-calorie drinks.
• In the morning, mix the HalfLytely solution as follows: Add lukewarm drinking water to the top of the line on
bottle.
– You may add a flavor packet provided with the HalfLytely kit.
– Close the bottle with its cap and shake the bottle to dissolve the powder.
– The mixed solution will be clear and colorless even if you added a flavor packet.
• Put the mixed solution in the refrigerator. Patients have told us that it tastes better chilled. Do not mix the
HalfLytely earlier than the morning before your test.
At 12:00 p.m.
• Take the bisacodyl tablet by mouth with a glass of water.
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At 6:00 p.m.
• Drink all of the solution as follows:
– Drink one 8-ounce glass every 20 minutes, for a total of about 8 glasses.
– You must try to finish the entire bottle of HalfLytely.
– If you have nausea and vomiting, wait about 30 minutes. Then try to resume drinking the HalfLytely.
• Bowel movements usually begin within 1 hour of drinking the first dose. It takes longer in some people.
• Apply Vaseline ® or A & D ® ointment to the skin around your anus after every bowel movement. This helps
prevent irritation.
The Day of Your Procedure
Enter the hospital through the main entrance at 1275 York Avenue. Take the escalator up to the Main Level. Take
the “M” elevators to the 2nd floor. You will see two large glass double doors when you exit the elevator. This is
your destination. Please be on time for your appointment.
After registering, you will be asked to change into a patient gown. The doctor will explain the procedure and
answer your questions. If you take insulin for diabetes, please tell the doctor before the exam starts.
The Virtual Colonoscopy Procedure
You will be shown into the CT scan room and assisted onto the scanner bed. The doctor will insert a rubber tube
into your rectum. Air or carbon dioxide gas will be instilled to expand your colon. If the air or gas becomes
uncomfortable, tell the doctor. After the air or gas is instilled, a CT scan will be done.
After the Procedure
After the scan is completed, the tube will be removed. The air or gas will be expelled naturally, as when passing
gas. You will be able to get dressed and leave the CT scan area after your procedure. There will be no restrictions
on your activities or diet.
Your doctor will have the results of the exam in 24 to 48 hours.
©2001 Memorial Sloan-Kettering Cancer Center
1275 York Avenue, New York, New York 10065
Reviewed 2002; revised 2004, 2006; revised 2008,
2009, 2010
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