HF 7058

Getting Ready for Your Colonoscopy- Two-Day Prep Using PEG Solution Split -Dose and Magnesium Citrate

Important: Please read at least 1 week before your procedure.

1 Week Before Your Procedure


  • Arrange for an adult to drive you home. You will not be able to drive or return to work after your procedure.

  • You may take a cab or bus only if you have an adult who can go with you.

  • If you need help finding a way to get to and from your visit, contact Patient Resources at 608-821-4144.

Health Changes
Notify us of any major health changes, illnesses, or recent hospital stays. Call
(608) 890-5010 for procedures at DHC. For procedures at UW Hospital GI Procedure clinic, call (608) 263-8094.

Blood Thinning Medicine Changes
You may need to stop or adjust blood thinning medicines before your procedure. You must call the doctor who prescribes the medicine to discuss this, or we may not be able to complete your procedure.

Diabetes Medicines
Your medicine and your blood sugar testing may need to be changed during your prep time. You must call the doctor who prescribes the medicine to discuss this, or we may not be able to complete your procedure.

Iron and Multivitamins with Iron
taking 5 days before your procedure. (You do not need to contact your doctor first.)

In Case You Are Constipated
Those who are often constipated or have not had a clean colon for a past procedure may need extra prep. Please call to discuss this in more detail.

3 Days Before Procedure

Low Fiber Diet
Stop these foods and medicines:

  • Corn, popcorn, seeds or nuts

  • Uncooked vegetables, beans and lentils, potato skins

  • Fruits with skins or seeds

  • Whole grain breads, granola or high fiber cereals

  • Fiber supplements (like Metamucil®, Citrucel®, or Benefiber®)

  • Anti-diarrhea medicines (like Kaopectate®, Lomotil®, Pepto-Bismol® and Imodium® or loperamide)

See website for tips of what you can eat. www.uwhealth.org/digestivehealth

Pick up Bowel Prep
Call your pharmacy to let them know you will be picking up your bowel prep. Please pick up your bowel prep 3days before your procedure. Also pick up the 10 oz. bottle of magnesium citrate, this is bought over the counter. Do not mix the bowel prep until the day before the procedure.

2 Days Before Procedure

You may eat and drink until noon. After 12:00 noon, do not eat or drink solid food, milk or dairy products. You can have clear liquids until bedtime. Keep drinking to stay hydrated.

  • Clear Liquid Diet Rules

  • No creamers, milks or other dairy products.

  • No solid food.

  • Drink at least 8 glasses of clear liquids all day to stay hydrated.

  • No red or purple liquids.

Clear liquids include these “see-through” items:

  • Water, clear sports drinks like Gatorade®

  • Broth

  • Black coffee, tea, soda

  • Apple juice

  • Jell-O®

Avoid red or purple liquids (i.e. cranberry juice, grape juice, red or purple Jell-O®)

Take your daily medicine, except those you were told to stop. Take your medicines at least one hour before or one hour after drinking your prep.

Bowel Prep
At 3:00- 5:00PM
drink the full bottle of magnesium citrate. This may give you loose stools and mild cramping. How fast it starts to work depends on the person. It could take from 30 minutes to 8 hours. Keep drinking clear liquids only.

1 Day Before Procedure

This part of the bowel prep is done in 2 steps called split dosing.

Prepare the Bowel Prep
In the morning, mix the PEG solution by adding lukewarm water to the fill line. Cap the bottle tightly and shake to dissolve. Keep drinking clear liquids only.
Take your daily medicine, except those you were told to stop. Take your medicines at least one hour before or one hour after drinking your prep.

  • Bowel Prep

  • If your arrival time is before 11am, drink ¾ of the jug (12 cups) starting between 4 pm and 6 pm. Drink about 1 cup (1 cup = 8 oz.) every 10-20 minutes.

  • If your arrival times is after 11:30 am, drink ½ of the jug (8 cups) starting between 6 pm and 8 pm. Drink about 1 cup (1 cup = 8 oz.) every 10-20 minutes.

  • Stop drinking if you feel sick to your stomach. Start again as soon as you are able at a slower rate. Once you have finished the amount listed above based on arrival time, put the rest of the prep in the fridge.

  • Keep drinking clear liquids to stay hydrated.

Procedure Day


  • Stay on clear liquids

  • Stop drinking liquids 4 hours before your arrival time

  • No Food

Bowel Prep

  • Start to drink the rest of your prep 5 to 6 hours before you arrive.

  • You must be finished drinking the entire gallon 4 hours before you arrive. As you finish the prep, your stools should be watery clear or yellow, with no solids (flecks of stool are OK). If you are still passing solid or brown stools, call us at (608) 890-5010.

  • Allow time for prep to work before leaving home.

What to Bring

  • CPAP or BiPAP and any inhalers that you use.

  • Eyeglass or contact lens case, denture cup

  • Ostomy supplies

  • Wear comfortable clothing.

  • Do not bring valuables, money, or jewelry.

Tips for a Successful Colon Prep

  • Plan on each dose taking several hours.

  • Stay near a bathroom. Stock up on soft toilet paper and reading materials.

  • If you don’t like the taste of the prep, you may add yellow lemonade Crystal Light® to the mixture. We suggest mixing it into 1 glass at a time.

  • Drinking the prep through a straw may help improve the taste.

  • Between glasses, you can chew gum or suck on slices of lime or lemon or hard candies. Avoid red or purple candy.

  • After you mix the prep, we suggest you put it in the fridge. Take it out of the fridge at least 2 hours before you start drinking it, so you won’t feel too cold.

  • If you get chilled, try putting a blanket in the dryer to warm it up before using.

What to Expect

  • Your visit at UW Digestive Health Center will last about 2 -3 hours, from the time you check in until the time you can leave.

  • It is up to you if your driver stays in our waiting room or in your private room where private medical information will be discussed.

  • Before the procedure, the doctor will talk with you, answer questions, and ask you to sign a consent form.

  • An IV will be placed by a nurse.

  • Medicines will be given during your procedure to help you relax and keep you comfortable.

  • After your procedure, your doctor will talk with you about the results and give you a report. We strongly suggest that you have your driver wait in your private room to hear the results with you. It is your choice to have your driver with you when the doctor talks to you.

  • You will feel sleepy when you leave.

  • Plan to spend the day resting at home. You cannot drive or return to work due to the sedation medicines. Most patients can return to their normal activities the day after their procedure.

  • If biopsies are taken or polyps removed, you can expect to get lab results 1-2 weeks after your procedure, either by phone or by mail.

  • It may take up to a week for your bowel habits to return to your normal.

When to Call

  • If you are unable to keep your appointment, let us know 5 days before.

  • Any questions about your bowel prep

  • If you are having bad stomach pain, or dizziness

  • If you don’t have a bowel movement

Who to Call
UW Health Digestive Health Center
7AM-5PM- weekdays
(608) 890- 5010
Out of area- (855) 342-9900
University Hospitals GI Procedure Center
7:30AM- 5:00PM- weekdays
(608) 263- 8094
Out of area (800) 323-8942

After hours and on weekends, call the numbers listed and you will be connected with paging. Ask for the Gastroenterology (GI) doctor on call. Give your name and phone number with area code. The doctor will call you back.

See website to find out more such as, prep video, diet tips, and prep worksheet. www.uwhealth.org/digestivehealth

If you are a patient receiving care at UnityPoint – Meriter, Swedish American or a health system outside of UW Health, please use the phone numbers provided in your discharge instructions for any questions or concerns.