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Virtual Colonoscopy


A virtual colonoscopy is a procedure to examine the inside of your colon (large intestine). Healthcare providers also use a CT scan or MRI to take pictures of your colon. If you have CT scan, air or carbon dioxide (gas) is put in using a small, bendable tube into your rectum to expand your colon. In an MRI colonoscopy, warm water or solutions with dye may be used so healthcare providers can clearly see the inside of your colon.


Before your procedure:

  • Informed consent is a legal document that explains the tests, treatments, or procedures that you may need. Informed consent means you understand what will be done and can make decisions about what you want. You give your permission when you sign the consent form. You can have someone sign this form for you if you are not able to sign it. You have the right to understand your medical care in words you know. Before you sign the consent form, understand the risks and benefits of what will be done. Make sure all your questions are answered.
  • An IV is a small tube placed in your vein that is used to give you medicine or liquids.
  • Pre-op care: You may be given medicine right before your procedure or surgery. This medicine may make you feel relaxed and sleepy. You are taken on a stretcher to the room where your procedure or surgery will be done, and then you are moved to a table or bed.

During your procedure:

  • You are asked to lie on your stomach or left side. You will need to raise one or both knees toward your chest. Your healthcare provider may give you medicine that helps relax your colon. Your healthcare provider will examine your anus and use a finger to perform a digital rectal exam (DRE) to check your rectum. He will also feel for your prostate if you are a man. He may inject a dye through your IV to see your colon better. A thin, flexible tube is gently inserted in your rectum. If a CT colonoscopy will be done, carbon dioxide is put into the tube. In an MRI colonoscopy, warm water or solutions with dye are passed through the tube.
  • During your procedure, the bed you are lying on is moved inside the CT or MRI tube. Pictures are taken as the bed or table moves and as you change positions. You are asked to lie on your back or stomach. If the bowel is not expanded enough, more air or gas is pumped into your rectum. Hold your breath and stay still as each picture is taken. When the procedure is finished, your bed is moved out of the CT or MRI tube. The small tube in your rectum is slowly removed.

After your procedure:

You may pass some air that is left in your colon. When your healthcare provider sees that you are okay, you will be allowed to change clothes and go home. If your healthcare provider wants you to stay in the hospital, you will be taken back to your hospital room.

  • Eat healthy foods: Choose healthy foods from all the food groups every day. Include whole-grain bread, cereal, rice, and pasta. Eat a variety of fruits and vegetables, including dark green and orange vegetables. Include dairy products such as low-fat milk, yogurt, and cheese. Choose protein sources, such as lean beef and chicken, fish, beans, eggs, and nuts. Ask how many servings of fats, oils, and sweets you should have each day, and if you need to be on a special diet.
  • Drinking liquids: Men 19 years old and older should drink about three Liters of liquid each day (about 13 eight-ounce cups). Women 19 years old and older should drink about two Liters of liquid each day (about 9 eight-ounce cups). Follow your caregiver's advice if you must change the amount of liquid you drink. For most people, healthy liquids to drink are water, juices, and milk. If you are used to drinking liquids that contain caffeine, such as coffee, these can also be counted in your daily liquid amount. Try to drink enough liquid each day, and not just when you feel thirsty.
  • Medicines: You may need any of the following:
    • Pain medicine: Caregivers may give you medicine to take away or decrease your pain.
      • Do not wait until the pain is severe to ask for your medicine. Tell caregivers if your pain does not decrease. The medicine may not work as well at controlling your pain if you wait too long to take it.
      • Pain medicine can make you dizzy or sleepy. Prevent falls by calling a caregiver when you want to get out of bed or if you need help.
    • Stool softeners: This medicine makes it easier for you to have a bowel movement. You may need this medicine to treat or prevent constipation.
  • Monitoring: Healthcare providers may check for your pulses on your arms or wrists. This helps healthcare providers learn if you have problems with blood flow after your procedure. You may also have the following:
    • Vital signs: Caregivers will check your blood pressure, heart rate, breathing rate, and temperature. They will also ask about your pain. These vital signs give caregivers information about your current health.


  • CT scanning exposes you to radiation that is released when x-ray pictures are taken. If dye is used, it may cause you to have headaches, nausea, vomiting, flushing, or itchiness. You could also have an allergic reaction to the dye. You may feel a little pain or discomfort as the small tube is placed inside your rectum. Your colon may get perforated (torn) due to increased pressure. If this happens, you will need to stay in the hospital and have surgery on your colon.
  • Without this procedure, diseases may not be diagnosed and proper treatment may be delayed. The signs and symptoms you have may continue and worsen. You may have problems eating, digesting food, or moving your bowel. This may lead to other serious medical problems, such as a blockage of your colon.


You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.