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How to Prepare for Your Colonoscopy with Miralax® (polyethylene glycol) & Magnesium Citrate

Please read this entire handout carefully today to prepare for your scheduled colonoscopy procedure. There may be medication instructions that begin as early as five days before your procedure. This handout has detailed instructions for before and after your procedure. We want to make sure you are well prepared for your colonoscopy. If you have any questions, please call us at the number your doctor provided. We would be glad to answer any questions about your scheduled procedure. 

 

If you have kidney disease, do not use this prep. Ask for another prep from your doctor.

 

Before Your Procedure

Getting Your Miralax®, Magnesium Citrate and other laxatives (if directed) at the Pharmacy
At least one day before your procedure, pick up the following:

  • Over the counter bottle of Miralax® (238 grams)
  • Over the counter laxative called magnesium citrate (10 ounces). You will need one large pitcher that holds 2 liters of fluid. This is for the Miralax® preparation.
  • Only if your doctor directs, buy over the counter laxative bisacodyl (brand name: Dulcolax®). You will need to take 2 tablets. Do not buy docusate, which is a stool softener, and is not the same.
  • Only if your doctor directs, buy over the counter simethicone (brand names: Gas-X®, Mylicon®, Phazyme®) drops or pills.


Medications and Supplements

  • If you take any medications or vitamins (especially heart or diabetes medications or blood thinners), please speak with your doctor. Your doctor will let you know if/when you should stop taking your medication(s).
  • Take your medications as prescribed with small sips of water (if needed) the day of your procedure. Do this unless otherwise instructed by your doctor.


Beginning Three Days Before Your Procedure

  • Do not eat corn, quinoa, lentils, peas, beans, fruits with seeds, leafy vegetables, red beets, nuts or anything with seeds. Do not eat these foods for three days before your colonoscopy. This way you are clear and clean before your procedure.


One Day Before Your Procedure

  • Begin a clear liquid diet as soon as you wake up (for example, water, clear juices, soda, sports drinks, plain tea or black coffee). Do not eat or drink food that is not clear. Do not drink milk, milkshakes, fruit or vegetable smoothies, juices that are not clear or alcohol until after your procedure. This is for your colon to be clear and clean for your procedure.
  • Do not drink red beet juice or any liquid with seeds.
  • Drink as much liquid as you can. This will help make sure you are prepared for and feel strong on the day of your colonoscopy.


Starting the Preparation (One Day before the Procedure)

Note: Prep start times may differ by doctor. Your doctor will confirm start times with you.

Step 1: Prepare the Miralax® Solution

  • After breakfast, prepare your Miralax solution: add the entire 238-gram bottle of Miralax into a large pitcher and fill the pitcher with at least 64 ounces of clear liquid (for example, Gatorade, Crystal Light, apple juice, seltzer, ginger ale).


Step 2: Drink the Miralax® Prep

  • Only if your doctor directs, take the 2 bisacodyl (Dulcolax®) laxative tablets 2-4 hours before starting to drink your prep. Drink the tablets with 8 ounces of water or other clear liquids.
  • At 5:30pm, begin drinking the Miralax by drinking 8 ounces every 10 to 15 minutes until the solution is finished.

 

The Day of Your Procedure


Step 3: Drink the magnesium citrate

  • Five hours before your procedure, drink the 10-ounce bottle of magnesium citrate along with at minimum 8 ounces of water (mixed or separately). Only if your doctor directs, add 2 droppers full of simethicone liquid to the bottle of magnesium citrate. If you bought simethicone pills, take 2 pills and then start drinking the bottle of magnesium citrate.

  • Stop all drinking/eating (including the prep, chewing gum, and hard candies) 2 hours before your scheduled procedure.

  • Bring a list of your medications with you on the day of your procedure.

  • Take your medications as prescribed with small sips of water (if needed) the morning of your procedure. Do this unless instructed otherwise (refer to the Medications and Supplements section on the first page). Discuss with your doctor the medications you can or cannot take.

  • Allow extra time to travel to your procedure. You may need to stop and use a restroom along the way.

 

Helpful Tips

  • Please note that some patients may have nausea with vomiting during the prep. If this happens to you, take a break from drinking the prep for about 30 minutes. Then start drinking it again but at a slower pace. You must drink the entire dose.
  • Keeping the prep in the fridge for a while may make it taste better.
  • Drinking the prep through a straw may make it easier to drink.
  • Walking between drinking each glass can help ease bloating.
  • Sucking on hard candies may help.
  • Using baby wipes instead of toilet paper may feel better.
  • You may apply some Vaseline® or Desitin® to your anal area / between your buttocks before starting the prep. This helps with irritation. Reapply as needed. You can also use over the counter hydrocortisone creams, hemorrhoid treatments or Tucks®.
  • Stay close to a toilet during the prep. You may have several bowel movements during this time. The prep often works within 30 minutes but may take as long as 3 hours.
  • Remember: The key to a good prep is to drink plenty of liquids throughout the day. This not only cleans out your colon but also keeps you strong!

 
After Your Procedure

  • We will give you medication to sedate you during your colonoscopy. This medication will relax you and make you feel comfortable. You must arrange for a responsible adult to escort you home for your safety. If you do not have a responsible adult who will pick you up or escort you via public transportation after your procedure, we must cancel it.
  • If we remove a large polyp during your procedure, you may have a 10-day restriction on travel. Be aware of this in case you may have to change your routine and schedule during this time.
  • Do not drive, ride a bike, make important legal/business decisions, be solely responsible for the care of small children, or operate heavy machinery for the rest of the day. This is because you may feel drowsy.
  • Unless your doctor directs otherwise, you may resume your normal diet following the procedure.

 

© NYU Langone Health. All rights reserved. Reviewed for health literacy. This information is not intended as a substitute for professional medical care. Always follow your health care provider's instructions.