Getting Ready for Colonoscopy Using PEG and Bisacodyl
What is a Colonoscopy?
A colonoscopy is an exam of your colon (large bowel). Your doctor uses a long, thin, flexible tube with a built in camera and light. This tube lets the doctor see the lining of your colon very clearly. If needed, the doctor can remove growths in the colon called polyps or take tiny samples of tissue to detect certain conditions.
Important – Read 1 week in advance.
Procedure may be cancelled if instructions are not followed.
1. 7 days before, you should stop taking the blood thinner Effient®
2. 5 days before, you should stop taking:
- Blood thinners, such as Coumadin® (warfarin) or Plavix® (clopidogrel).
3. 2 days before, you should stop taking the blood thinner Pradaxa®
Blood thinning pills should never be stopped without discussing this with the doctor who prescribes it for you. The doctor will give you instructions on how to safely do this. Contact us if you have questions.
4. Diabetic medicines (oral and insulin) will need to be adjusted for the
time you’re not eating as normal. Please discuss this with your primary
5. You must have an adult to drive you home or your exam will be
cancelled. You may take a cab or bus home only if you have a responsible
adult with you other than the driver.
6. Three days before your exam, avoid these foods (corn, peas, popcorn,
nuts, and fruits with skins or seeds) which are digested slowly. They
interfere with your prep and our ability to see your colon.
7. You will need to purchase bowel prep supplies at least 2 days before your
exam. You will be given a prescription for the PEG solution to fill at your
local drugstore. You will also need to buy two 5mg Bisacodyl laxative
tablets which are sold over the counter.
8. Plan ahead. For your exam you will be given sedatives which can greatly
affect your judgment. On the day of your exam, you will not be able to drive
or return to work. Do not make important personal or business decisions until
the next day.
9. Our staff will need to review your health history, prior surgeries, allergies,
and medicines taken. Please bring this information with you, including a list
of your medicines or your labeled medicine bottles.
10. If you use CPAP or BiPAP for sleep apnea, please bring it with you. We
will need your machine in order to sedate you safely.
11. If you have an implanted pacemaker or defibrillator, we will need specific
information about it before your procedure day. If you haven't already
given us this information, please call us during business hours (8:00 AM to
5:00 PM, Monday through Friday) at (608) 263-8097. Ask to speak to the
Day before your Exam
Follow your bowel prep instructions carefully. A clean colon is needed for your test to be accurate.
Prepare the Bowel Prep
1. In the morning, mix the PEG Solution by adding lukewarm water to the fill
line. Cap the bottle tightly and shake to dissolve contents.
2. You may add 2 packets of Crystal Light® yellow lemonade or a flavor pack if
one is provided. Do not add any other liquid or flavors. Crystal Light®
yellow lemonade may be added by the glass, if you prefer.
3. Refrigerate. It will taste better if chilled.
4. You will drink one half of the solution (2 liters).
1. You may eat your normal breakfast before 10:00 AM. After 10:00 AM, do
not eat solid food, milk, or dairy products.
2. You may drink clear liquids until bedtime. Keep drinking to stay hydrated.
Avoid red or purple liquids. These resemble blood in your colon.
3. Clear liquids include:
o Apple or white grape juice (no tomato, grapefruit, cranberry, grape, or orange juice)
o Gatorade® (no red or purple)
o Jell-O®(without fruit, no red or purple)
o Tea or coffee (no cream or milk; sugar is okay)
If you take medicines, take them 1 hour before drinking the bowel prep or 1 hour after you are done. Do not take them while you are drinking the prep.
Plan on your bowel prep taking 2 to 8 hours. Stay near a bathroom during this time.
At 3:00 PM to 5:00 PM
1. Take two 5mg bisacodyl tablets with water. Do not chew or crush them. Do
not take them within 1 hour of taking an antacid. You should begin to have
some abdominal cramping and liquid bowel movements within 1 to 6 hours.
2. Two hour after taking the bisacodyl tablets, start to drink the PEG
Solution at a rate of 8 ounces (1 cup) every 10 – 20 minutes until half the
bottle is gone. It works best when taken rapidly but you can drink more
slowly if you feel too full or nauseated. You may feel cold while drinking the
3. Stop drinking if you feel sick to your stomach and resume, as soon as you
are able, at a slower rate. Your prep is complete when you’ve finished half
of the gallon (2 liters). Please save the remaining solution in case your
stools are not adequately clear.
4. When finished with the prep, your bowel movements should be watery and
see-through, free of solids (flecks are OK). The color may appear clear to
yellow, green or tan.
5. Keep drinking clear liquids tonight to prevent dehydration.
For problems with your bowel prep, you can reach us at the contact numbers listed at the end of this handout. If severe, steady stomach pain occurs or you don’t expel any of the bowel prep, call the paging operator at (608) 262-0486 or toll free at 1-800-323-8942. Ask for the gastroenterology (GI) doctor on call.
Day of the Exam
1. No solid food, milk, or dairy products until after your exam.
2. Keep drinking clear liquids to prevent dehydration. You should have nothing by mouth for 4 hours before you arrive. You must stop drinking liquids for sedation to be given safely. It is OK to rinse your mouth. .
3. Take your normal medicines with a small sip of clear liquids up to 1 hour before you arrive. Do not take the medicines listed under “Getting Ready”.
4. Follow the arrival and registration instructions in your cover letter. If you are delayed, call us at (608) 263-8094 to let us know you are going to be late. If you are over 30 minutes late, we may have to cancel and reschedule. We do our best to stay on time.
5. Plan to be with us about 2 to 3 hours. Your driver will need to be available in our waiting room or by phone during this time. You may not leave the recovery room without a responsible adult.
A nurse will review your health history and place an IV. The IV is used to give you medicines which make you feel drowsy and relaxed during your test. The procedure will take 45 to 60 minutes. You will then go to our Recovery Room for about an hour. Your driver may sit with you there. Once awake, you will be given something to drink. Your doctor will discuss results with you before discharge. You and the doctor who referred you will receive a copy of the report. If you have a colostomy, please bring extra supplies for after the test.
After the Colonoscopy and for the Rest of the Day
▪ Do not return to work.
▪ Do not use hazardous machinery.
▪ Do not make any important decisions.
▪ Plan to rest.
▪ Do not drink alcohol.
▪ Do not drive.
You should be able to resume normal daily tasks on the day after your test.
You may feel bloated for a few hours. This is caused by air that was put into your colon during the exam. It’s best to wear loose fitting clothes.
Most often, you may eat and drink what you wish after the exam. Plan on starting with something light.
How to Contact Us
GI Procedure Center, 7:00 AM to 5:00 PM weekdays, (608) 263-8094.
After clinic hours, this number will connect to the paging operator. Ask for the Gastroenterology (GI) doctor on call. Leave your name and phone number with the area code. The doctor will call you back.
If you live out of the area, call 1-800-323-8942.
If you are not able to keep your appointment, please let us know 5 days in advance.
University of Wisconsin Hospital & Clinics Madison Surgery Center
600 Highland Avenue 1 South Park Street
C5/2 Gastroenterology Clinic 3rd Floor
Madison WI 53792 Madison WI 53715
The Spanish version of this Health Facts for You is #6998.
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: 06/06/2013
Copyright © 05/16/2011 University of Wisconsin Hospitals and Clinics Authority. All rights reserved. Produced by the Department of Nursing. HF#6878
Print Health Fact For You