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Miralax Split-Dose Bowel Preparation Instructions for Colonoscopy

What is Miralax?

Miralax (polyethylene glycol) is a bowel cleansing product used to cleanse the bowel prior to colonoscopy and for constipation. It is over-the-counter and can be bought at any pharmacy. Purchase a 14 dose bottle and a 7 dose bottle OR a 20 dose bottle and you will use 18 doses from it.

5-7 Days Prior to Your Colonoscopy

  1. Stop taking any medicine containing iron or any iron supplements.
  2. If you are taking Coumadin/Warfarin, Plavix, Effient, Pletal. or any other blood thinning medication, please ask your prescribing doctor to see if you are able to stop those medications 5-7 days prior to your procedure. If you are not able to come off those medications, please contact our office prior to your procedure.
  3. Please stop any additional aspirin or NSAIDS (Aleve, Motrin, Advil, etc) 5 days prior to your colonoscopy if possible. You may continue to take a daily aspirin if needed for a medical condition. 
  4. Stop fish oil, vitamin E, and any other oily vitamin 7 days prior.
  5. Avoid drinking alcohol.
  6. Try to maintain a low fibrous diet. Avoid items like corn, popcorn, broccoli, beans, and dried fruit.

The Day Before Your Colonoscopy

  1. Ensure you have purchased the Miralax product.
  2. You are only allowed to drink a clear liquid diet the day prior to your colonoscopy.
  3. DO NOT eat any solid foods the day prior to your exam.

Clear liquids include the following and are not limited to:

NOTHING RED IN COLOR, water, Jello (not red), soda (not red), white cranberry juice, tea, coffee (black only), Kool-aid (not red), apple juice, white grape juice, broth (chicken, vegetable, beef), Crystal Light , MIO or other drink flavorings, Lemonade, Popsicles, and Gatorade.

It is very important to drink plenty of fluids the day prior to your exam!

4:00pm the Day Prior to Your Colonoscopy

  1. Begin your bowel preparation by drink 17 grams of Miralax powder from the cap provided, mixed with 8 ounces of clear liquid from the list above, stir and drink. Repeat this process every 15-20 minutes until 14 doses are consumed.
  2. This should take you about 2-4 hours to complete. If you feel full or nauseated by drinking the solution then slow down and finish it before midnight. It is very important to drink the 14 doses the night BEFORE your procedure.

The Day of Your Colonoscopy

  1. Finish drinking the remaining 4 doses of Miralax the morning of your procedure. It is important that you have finished the prep 4 hours prior to your scheduled colonoscopy.
  3. If you are taking medications for high blood pressure or heart disease, it is important that you take them early in the morning on the day of your exam with a sip of water.
  4. Have someone drive you home from the procedure; you may be here 2 to 3 hours. Please make sure your driver will be available by phone if they are unable to wait.
  5. If you are of child bearing years, you will need to perform a urine pregnancy test prior to sedation. This will be done at the Surgery Center.

Common Questions

  1. Why is it important to drink a split dose bowel preparation?
    • This formulation of bowel preparation has shown to be better tolerated by patients and produce better results than other bowel preparations.
  2. Why is it important to have a clean bowel for my colonoscopy?
    • Without a clean bowel, the physician performing your colonoscopy has a higher chance of not seeing small polyps or even cancer that could be obscured by stool.
  3. Will I be incontinent the morning of my exam?
    • NO. The morning dose of Miralax usually works quicker and lasts shorter than night dose.
  4. Are there other bowel cleansing preparations out there?
    • Yes, however we believe this to be the safest and best tolerated preparation available at the current time. If needed, we can prescribe other preparations.

If you are scheduled at St Mary’s you will get a phone call the night prior to your exam for pre-op questions.

If you have any questions about your colonoscopy or how to take your bowel preparation, please do not hesitate to call our office: (573) 556-5736.

It is important that my office be notified of any reschedule or cancellation at least 2 days prior to scheduled procedure. There may be a $75 reschedule fee if this is not done.