Preparing for Your Virtual Colonoscopy (VC PEG Prep)
What is Virtual Colonoscopy?
Virtual Colonoscopy (VC), also referred to as CT colonography, is a less-invasive, safe exam used for colon polyp screening. The entire colon lining can be seen with VC. A computed tomography (CT) scan creates a 3-D picture of the inside of your colon which allows the doctor to “fly” through the interior of the colon without having to insert a scope. VC also allows the doctor to take a limited look outside the colon for problems in the abdomen and pelvis. The main purpose of this exam is to screen for growths (polyps) in the lining of the large intestine (colon and rectum). Adults ages 50 years and over should have screening for colon polyps.
If a large polyp or growth is found in your colon, a standard colonoscopy may be needed to remove the polyp. “Large” polyps are those 1 cm (about ⅜ inch) or greater and should be removed because they have a higher chance of turning into cancer. A growth of this size is present in less than 5% of all patients. A nurse will arrange for the standard colonoscopy, if needed. If this occurs, you will need to have someone drive you home. By scheduling the standard colonoscopy on the same day or next day, a second bowel prep is not needed.
Doctors at UW Hospital & Clinics can also watch a small colon polyp over time. Smaller polyps, 6 mm to 9 mm (about ⅓-¼ inch), can be safely watched by having a follow up VC exam in 3 years. But small polyps can also be removed by standard colonoscopy, the same day or later, if desired.
Getting Ready for your VC Exam
If you would like to have the option of a same-day standard colonoscopy if a polyp is found, stop taking iron tablets five days before the exam. Taking iron does not affect your VC exam, so if you would not be able to have a standard colonoscopy the same day because you would not have a driver, or you have other plans, you may continue taking it. If you have any questions or concerns about stopping a medicine please contact your doctor. You may take all other prescribed medicines before your VC (if you have diabetes or are taking prescription blood thinners or anti-platelet medications, see the boxes on page 2).
Three days before the exam, try to avoid foods that are digested slowly (corn, popcorn, potato skins, nuts, fruits with skins and seeds, vegetables-except those that are well-cooked or pureed) because they may interfere with your prep.
If you have DIABETES, please call your doctor to discuss how your diabetes medicine (oral diabetes pills and/or insulin) doses should change before the VC.
Test your blood sugar more often the day before this test. Also check your blood sugar the morning of your test. If your blood sugar level is low (less than 70 mg/dl) or if you have symptoms, take some glucose tablets or drink 4 ounces of a clear liquid that contains sugar. Always recheck your blood sugar level to make sure it stays above 70. We may still be able to do the VC unless you need to eat solid food to keep your blood sugar at a normal level. If the blood sugar ever gets too high or too low and you can’t bring it back to normal, call your primary care or diabetes doctor.
If you take PRESCRIPTION BLOOD THINNERS OR ANTI-PLATELET MEDICINES, do not stop taking them unless your doctor tells you to stop them. Some examples include: Coumadin® (warfarin), Plavix® (clopidogrel), Effient® (Prasugrel), Pradaxa® (Dabigatran). VC is often recommended for patients taking these types of medications because it is felt to be too great a risk to stop the blood thinner for a standard colonoscopy. VC can safely evaluate your colon without stopping these medications. If a polyp is found that should be removed, we will consult with your doctor who can set up the standard colonoscopy at a later date.
If your doctor tells you to stop your blood thinner or anti-platelet medicines so that you can have a same-day standard colonoscopy if a polyp is found, you must discuss how long to stop the medicine and any special instructions to do so safely with the doctor who prescribed the medicine for you.
Please stop iron tablets 5 days before your VC exam, only if you will also be stopping the blood thinner or anti-platelet medication. Otherwise you may keep taking iron.
|If you get DIVERTICULITIS before your VC exam, contact your doctor first for treatment. Then contact the VC office to reschedule your exam for at least six weeks after your treatment is complete to allow your colon to heal.|
The Day Before Your Exam (Prep Day)
Proper bowel cleaning is needed for the best exam! To get a clean and empty colon you will start to prepare the day before your exam. Both a clear liquid diet and the contents of the bowel prep kit are needed to clean out the colon. The bowel prep kit contains a laxative and contrast medicines. The laxative will help clean out the bowel for the exam. The contrast agents will help to highlight any stool left in your colon on the VC pictures.
Starting at midnight the entire day before your exam (prep day), you may drink as many clear liquids as you want unless you are under a fluid restriction by your doctor. If you are under a fluid restriction, please keep this in mind as you plan for the day. The GoLYTELY® described below does not count toward this restriction. Drink only clear liquids for breakfast, lunch, dinner, and snacks. Do not eat any solid foods. Drink plenty of fluid to avoid dehydration. Avoid red or purple liquids (i.e., red Jell-O®, cranberry juice, purple sports drinks). Clear liquids include:
Gatorade®, Powerade®(we suggest sports drinks with electrolytes to help with hydration)
Water, tea, or coffee (no cream or milk; sugar or honey is okay to add)
Vitaminwater®, Crystal Light® Jell-O®, Popsicles® (no fruit or cream added)
Bouillon or broth (chicken, beef, or vegetable)
Apple, white cranberry, or white grape juice (no orange, tomato, grapefruit, or prune juice)
Soda such as Sprite®, 7-Up®, ginger ale, or any cola
Clear hard candy, gum
Lemonade (with no pulp), iced tea
Clear liquid protein drinks such as Ensure Clear TM, or Resource® Breeze
How to Prepare GoLYTELY® Solution
• Please read the directions on the GoLYTELY® bottle. Add water to the “fill” mark on the bottle. Shake it until all the powder is dissolved. Do not add ice. Do not add any other liquids or flavors except, if desired, two packets of Crystal Light® yellow lemonade powder with Nutrasweet®. You may also try flavoring by the glass, instead of adding the Crystal Light® Lemonade powder to the entire bottle, in case you do not like it. Or, you may drink the GoLYTELY® without any flavoring.
• You may find it tastes better if it is chilled. Refrigerate, but do not add ice. Because you are drinking a large amount of liquid quickly, you may become chilled. This is normal. It can be helped by wearing warm clothing, covering up with a blanket warmed in the dryer, or drinking it at room temperature.
Bowel Prep Instructions: If you take other medicines, don’t take them while drinking GoLYTELY®. Take them at least 1 hour before starting GoLYTELY® or at least 1 hour after you finish drinking the GoLYTELY®. If you are under a fluid restriction from your doctor, please note that the GoLYTELY® does not count towards this restriction. GoLYTELY® does not get absorbed from your colon, it just flushes through.
(Step 1) At 8 AM or before: Take the four Bisacodyl® tablets (5 mg each) with 1 glass (8 ounces) of clear liquid. Do not chew or crush them. Do not take them within 1 hour of taking an antacid. This will gently help move your bowels to help the laxative taken in Step 2 work better. You can take these tablets and still do normal activities because they will rarely cause diarrhea.
(Step 2) – Start anytime between 12 Noon and 2 PM: Be sure to prepare the entire bottle of GoLYTELY® as instructed above. Please note that it may take some people longer to drink GoLYTELY®, so adjust the start time based on how well you think you will be able to tolerate the prep. Keep in mind that you should try to be cleaned out of stool by about 6 pm.
| Helpful Hints:
• Drink with a straw to lessen the taste
• Try gum or clear hard candy between glasses
• For a sore bottom after a bowel movement, cleanse with baby wipes and apply a protective ointment such as A+D® or Vaseline®. TUCKS® medicated cooling pads may also provide relief.
Start to drink at least one 8-ounce glass every 10 minutes. If you feel sick to your stomach, stop drinking until the nausea passes. Begin to drink again, but at a slower rate (one 8-ounce glass every 15-20 minutes).
About one hour after you start to drink the GoLYTELY® you will likely begin to have diarrhea. You will want to stay close to a bathroom. You may have some cramping in your lower abdomen. This is normal. If you start to have severe, steady stomach pain, get lightheaded or dizzy, or you don’t expel any of the GoLYTELY®, call your primary care doctor.
When you have completed half of the bottle of GoLYTELY®, you may stop if your bowel movements are watery and free of solids (flecks are OK). The color may appear clear to yellow, green, or tan, but must be see-through. If your bowel movements are not as described, continue to drink the GoLYTELY® until you feel your bowels are cleaned out well. Most people will only need to drink half the bottle of GoLYTELY®, but some may need to drink the entire bottle to clean out the colon and get the best exam.
If you are done drinking the GoLYTELY® by 6 PM, then
(Step 3) At 7 PM: Drink the entire 225 mL bottle of liquid barium sulfate suspension found in the prep kit. This is a contrast medicine used to highlight any leftover stool on the CT images. You may keep drinking clear liquids as desired.
(Step 4) At 9 PM: (Choose one option)
o Option A: Drink 1 bottle (60 mL) of diatrizoate undiluted. You may find it tastes better if you quickly drink it. Follow it with 1 glass (8 ounces) of clear juice, soda, or water. This will dilute the medicine in your stomach.
o Option B: Mix 1 bottle (60 mL) of diatrizoate in 1 glass (8 ounces) or more of clear juice, soda, or water. If you dilute the medicine, you must be able to drink the entire amount, but it is not necessary that you drink it quickly.
The diatrizoate is another contrast medication that helps enhance the VC pictures.
If you are not able to complete the above time schedule
If at 6 pm you still have more GoLYTELY® to drink and are not cleaned out of stool, keep drinking it. One hour after you’re finished, drink the barium sulfate (Step 3). Two hours after that, drink the diatrizoate (Step 4).
Bowel Prep Complete!!!
You may keep drinking clear liquids until midnight.
The Day of Your Exam
Do not eat or drink anything after midnight on your exam day until you are advised to after your exam. You may take your daily medicines as prescribed with small sips of water.
If you have diabetes, test your blood glucose level more often when you can’t eat as well as before your exam. You should adjust your insulin or oral diabetes pills as discussed with your doctor. Resume your normal schedule after you receive the exam result phone call and are eating again. If your blood glucose level is low (less than 70 mg/dl) or you have symptoms, please drink a clear liquid that contains sugar or take glucose tablets. Always recheck your blood sugar level to make sure it stays above 70. We can still do the exam unless you need to eat solid food to maintain your blood glucose. It is better to maintain your blood glucose than to have the exam. We can always schedule your VC in the future.
You do not need to have a family member or friend drive you to and from the VC exam, as you will not be given any medicine that will make you sleepy. If you need a standard colonoscopy the same day, then you will need to arrange for someone to drive you for that test.
During the VC Exam
The VC exam most often takes 15 minutes or less to complete, but allow yourself up to 45 minutes total for changing clothes and talking with the CT technologist. You will not need pain or sedation medicine or an IV for this exam. You will be asked to change into a hospital gown and then taken to a CT exam room where you will lie on the CT exam table. A small tube will be gently placed a very short distance into your rectum (this feeling is like having a digital rectal exam). Carbon dioxide will be placed slowly into your colon. The exam should not be painful, though you may have some abdominal fullness, discomfort, or cramping during the exam. You may feel the urge to have a bowel movement. These feelings should go away as soon as the exam is over. Pictures are taken of your abdomen and pelvis while you are lying on your back and then on your stomach. You will be asked to hold your breath for about 10 seconds while the CT scanner takes pictures.
After the Exam
You will be asked to give the CT technologist a phone number where the VC team can call you with your colon results. Many patients return to work or other activities after the exam is over.
• If you wish to have a polyp removed on the same day as your VC, please do not eat or drink until you hear from us. If you need to have a standard colonoscopy, the VC team can arrange this second exam for the same day as long as you have not eaten or had any liquids to drink.
• If you take prescription blood thinners, anti-platelet medicines, or do not wish to have a same-day standard colonoscopy, you may resume your normal diet right after the exam. If a polyp is found that should be removed, standard colonoscopy will be set up at a later date by your doctor’s office.
A VC team member will call you with the colon results in about two hours. If you do not have colon polyps, you will be told to return to your normal diet and any medicines you may have stopped. If you have colon polyps, a member of the VC team will review options with you and help arrange further care as needed.
VC also allows the doctor to take a limited look outside the colon for problems in the abdomen and pelvis. If any other problems are seen outside your colon, the results will be sent to your doctor in the full VC report. If you have not heard from your doctor about any other results within 2 weeks, we suggest you call his or her office to follow-up.
VC Program Assistant: 608-263-8587
VC Nurse: 608-263-9630
If you have an urgent concern after normal business hours please contact your primary care doctor’s on call service. If your referring doctor is from outside the UW Health system, you may call the paging operator for urgent VC related concerns at 608-263-6400 and ask for the radiology resident on-call.
If you are in need of immediate medical help, call 911 or go to the nearest Emergency Room.
If you need to reschedule for any reason please call 608-263-9729.
The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Any duplication or distribution of the information contained herein is strictly prohibited.
Last Updated: 11/01/2013
Copyright © 11/01/2013 University of Wisconsin Hospitals and Clinics Authority. All rights reserved. Produced by the Department of Nursing. HF#6293
Print Health Fact For You