How to Prepare for Your Colonoscopy Using MiraLAX®

Time to Read: About 11 minutes

This information will help you get ready for your colonoscopy using polyethylene glycol (MiraLAX®).

About Your Colonoscopy

A colonoscopy is a test that lets your doctor see inside your colon (large intestine). Your doctor will use a colonoscope to see inside your colon. This is a flexible tube with a camera on the end. The images will appear on a video monitor.

During your procedure, your doctor can:

  • Remove a small sample of tissue (biopsy) for testing.
  • Remove a polyp (growth of tissue).
  • Take photos of the inside of your colon.

Your colon must be empty for your procedure. Your doctor may not be able to see polyps or other problems if there’s stool (poop) inside your colon. You may need to have the procedure again if this happens.

Follow these instructions carefully. If you have any questions, contact your doctor’s office.

1 Week Before Your Procedure
Ask About Your Medications

You may need to stop taking some of your medications before your procedure. Talk with your doctor about which medications are safe for you to stop taking. We have included some common examples below.

Anticoagulants (Blood Thinners)

Blood thinners are medications that affect the way your blood clots. If you take a blood thinner, such as to treat blood clots or to prevent a heart attack or stroke, ask the doctor who prescribes it for you when to stop taking it.

Examples of common blood thinners are listed below. There are others, so be sure your care team knows all the medicine you take. Do not stop taking your blood thinner without talking with a member of your care team.

  • Apixaban (Eliquis®)
  • Aspirin
  • Celecoxib (Celebrex®)
  • Cilostazol (Pletal®)
  • Clopidogrel (Plavix®)
  • Dabigatran (Pradaxa®)
  • Dalteparin (Fragmin®)
  • Dipyridamole (Persantine®)
  • Edoxaban (Savaysa®)
  • Enoxaparin (Lovenox®)
  • Fondaparinux (Arixtra®)
  • Heparin (shot under your skin)
  • Meloxicam (Mobic®)
  • Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil®, Motrin®) and naproxen (Aleve®)
  • Pentoxifylline (Trental®)
  • Prasugrel (Effient®)
  • Rivaroxaban (Xarelto®)
  • Sulfasalazine (Azulfidine®, Sulfazine®)
  • Ticagrelor (Brilinta®)
  • Tinzaparin (Innohep®)
  • Warfarin (Jantoven®, Coumadin®)

Diabetes Medication

Ask the healthcare provider who prescribes your diabetes medication what to do the day before and morning of your procedure. Tell them you will be following a sugar-free, clear liquid diet the day before your procedure.

Do not take the following medications the day before or day of your procedure:

  • Metformin (such as Glucophage® or Glumetza®).
  • Medication that has metformin in it (such as Janumet®).

Arrange for someone to take you home

You must have a responsible care partner take you home after your procedure. A responsible care partner is someone who can help you get home safely. They should be able to contact your care team if they have any concerns. Make sure to plan this before the day of your procedure.

If you don’t have a responsible care partner to take you home, call one of the agencies below. They’ll send someone to go home with you. There’s a charge for this service, and you’ll need to provide transportation. It’s OK to use a taxi or car service, but you still need a responsible care partner with you.

Agencies in New York Agencies in New Jersey
VNS Health: 888-735-8913 Caring People: 877-227-4649
Caring People: 877-227-4649

Get a Letter From Your Doctor, if Needed

You may need to get a clearance letter before your procedure. A clearance letter is a letter that says you can safely have the procedure. Your MSK doctor’s office must have your clearance letter at least 1 day before your procedure.

Automatic Implantable Cardioverter-Defibrillator (AICD)

Tell your MSK doctor if you have an AICD. You will need a clearance letter from your cardiologist (heart doctor).

Other Symptoms

You will need a clearance letter from your doctor if you have had any of these during the last 6 weeks:

  • Chest pain.
  • Trouble breathing that’s new or has gotten worse.
  • Fainting.

Buy Supplies

You will need to buy the following supplies for your bowel preparation:

  • 4 (5 mg) tablets of bisacodyl (Dulcolax®). These are usually sold as a box of 10 tablets.
  • 1 (238-gram) bottle of polyethylene glycol (MiraLAX ®).
  • 64 ounces of any clear liquid that isn’t red, purple, or orange. You will need to mix this with the MiraLAX. Keep it at room temperature.
    • A sports drink like Gatorade® or Powerade® is a good choice. Sports drinks will help replace electrolytes that you will lose during the bowel preparation.
    • If you have diabetes, be sure to get sugar-free clear liquids.

Buy Extra Supplies, If Needed

You may need to buy extra supplies if you answer yes to any of the following questions:

  • Do you tend to be constipated (have trouble pooping) or have less than 3 bowel movements a week?
  • Do you take narcotic (opioid) medications? If you’re not sure, ask your healthcare provider. Opioids include:
    • Fentanyl (Duragesic®, Subsys®)
    • Morphine (DepoDur®, Duramorph®)
    • Hydrocodone (Vicodin®)
    • Oxycodone (Oxycontin®, Percocet®)
  • Have you had a colonoscopy with a poor prep (stool in your colon) in the past?

If you answered yes to any of these questions, you will need to buy MiraLAX®. You can buy a box of 10 (17-gram) packets or a (119-gram) bottle of powder.

You will also need to buy more liquids for a full liquid diet. Read the section “2 Days Before Your Colonoscopy” for examples of what you can drink.

5 Days Before Your Procedure

Stop Taking Iron Supplements

If you take an iron supplement, stop taking it 5 days before your procedure. Iron supplements can cause color changes in your stool. This can make it harder for your doctor to see your colon clearly.

3 Days Before Your Procedure

Follow a low-fiber diet

Follow a low-fiber diet starting 3 days before your colonoscopy. During this time, do not eat:

  • Raw (uncooked) fruits and vegetables.
  • Whole kernel corn, including canned corn.
  • Whole grains (such as oatmeal, brown rice, quinoa, or wheat bread).
  • Seeds (such as poppy or sesame).
  • Nuts.

Talk With Your Endoscopy Nurse

A few days before your procedure, you will get a call from an endoscopy nurse. They will go over the instructions in this guide with you and ask you questions about your medical history.

The nurse will also review your medications and tell you which to take the morning of your procedure.

Use the space below to write them down.




2 Days Before Your Procedure

Keep following a low-fiber diet unless you:

  • Are often constipated.
  • Take narcotic medications.
  • Have had a colonoscopy with a poor prep in the past.

If any of those apply to you, stop following the low-fiber diet and follow these instructions:

  • Take 1 (17-gram) dose of MiraLAX 3 times a day. Mix 1 dose with 8 ounces of liquid each time. You can take one dose at breakfast, lunch, and dinner.
  • Follow a full liquid diet. On a full liquid diet, you can eat and drink the following:
    • Yogurt (without any pieces of fruit).
    • Fruit juices without pulp.
    • Soda.
    • Broth or cream soups that have been strained so there are no vegetable pieces.
    • Nutritional supplements.
    • Ice cream and fruit ices. These must not have any pieces of fruit, nuts, fudge, or peanut butter mixed in.

The Day Before Your Procedure

Prepare Your MiraLAX Bowel Preparation

On the morning of the day before your procedure, mix all 238 grams of the MiraLAX powder with 64 ounces of a room temperature clear liquid until the MiraLAX powder dissolves.

Once the MiraLAX is dissolved, you can put the mixture in the refrigerator. This is optional.

Do not mix the MiraLAX earlier than the morning of the day before your procedure.

Follow a Clear Liquid Diet

You will need to follow a clear liquid diet the day before your procedure. A clear liquid diet includes only liquids you can see through. You can find examples in the “Clear liquid diet” table.

When you’re on a clear liquid diet:

  • Do not eat any solid foods.
  • Do not drink anything red, purple, or orange.
  • Try to drink at least 1 (8-ounce) glass of liquid every hour while you’re awake.
  • Drink different types of clear liquids. Do not just drink water, coffee, and tea. This helps to make sure that you get enough calories and is an important part of your colonoscopy preparation.
  • If you have diabetes, drink only sugar-free clear liquids and check your blood sugar level often. If you have any questions, talk with your healthcare provider.
Clear Liquid Diet
OK to Drink Do Not Drink
Soups
  • Clear broth, bouillon, or consommé.
  • Any products with pieces of dried food or seasoning.
Sweets
  • Gelatin, such as Jell-O®.
  • Flavored ices.
  • Hard candies, such as Life Savers®.
  • Anything red, purple, or orange.
Drinks
  • Clear fruit juices, such as apple, white cranberry, lemonade, or white grape.
  • Soda, such as 7-Up®, Sprite®, ginger ale, or seltzer.
  • Gatorade®.
  • Black coffee.
  • Tea.
  • Water.
  • Juices with pulp.
  • Nectars.
  • Milk or cream.
  • Alcoholic beverages.
  • Anything red, purple, or orange.

Note the Time of Your Procedure

A staff member will call you after noon (12 p.m.) the day before your procedure. The staff member will tell you what time you should arrive for your procedure. If you’re scheduled for your procedure on a Monday, you will be called on the Friday before. If you do not receive a call, call your doctor’s office.

If you need to cancel your procedure, call the doctor who scheduled it for you.

Start Your Bowel Preparation

Step 1: At on the day before your procedure, take 2 bisacodyl (5mg) tablets by mouth with a glass of water.

Step 2: At , start drinking the MiraLAX mixture.

  1. At , drink 1 (8-ounce) glass of the mixture.
  2. At , drink 1 (8-ounce) glass of the mixture.
  3. At , drink 1 (8-ounce) glass of the mixture.
  4. At , drink 1 (8-ounce) glass of the mixture.

You will drink 4 glasses of the mixture in total.

  • When you’re finished, half of the MiraLAX mixture will be left. The time you drink the second half of the MiraLAX mixture will depend on your scheduled arrival time. Follow the instructions in Step 3.
  • Bowel movements usually begin within 1 hour of drinking the first dose, but it may take longer for some people.
    • Do not worry if you do not start having bowel movements after drinking the first half of the MiraLAX. Continue to drink liquids and start the second half of the MiraLAX as instructed.
  • Put petroleum jelly (Vaseline®) or A & D® ointment on the skin around your anus after every bowel movement. This helps prevent irritation.
  • Continue to drink clear liquids to stay hydrated and flush out your colon.

Step 3 (If you were told to arrive for your procedure before 11 a.m.):

If you were told to arrive for your procedure before , follow these instructions the night before your procedure:

At , take 2 bisacodyl tablets by mouth with a glass of water. Then, start drinking the second half of the MiraLAX mixture.

  1. At , drink 1 (8-ounce) glass of the mixture.
  2. At , drink 1 (8-ounce) glass of the mixture.
  3. At , drink 1 (8-ounce) glass of the mixture.
  4. At (midnight), drink 1 (8-ounce) glass of the mixture.

Be sure to finish the entire MiraLAX mixture.

  • You can continue to drink clear liquids until 4 hours before your scheduled arrival time.
  • Do not eat anything until after your procedure.

The Day of Your Procedure

Step 3 (If you were told to arrive for your procedure at or later):

If you were told to arrive for your procedure at or later, follow these instructions the morning of your procedure:

At , take 2 bisacodyl tablets by mouth with a glass of water. Then, start drinking the second half of the MiraLAX mixture.

  1. At , drink 1 (8-ounce) glass of the mixture.
  2. At , drink 1 (8-ounce) glass of the mixture.
  3. At , drink 1 (8-ounce) glass of the mixture.
  4. At , drink 1 (8-ounce) glass of the mixture.

Be sure to finish the entire MiraLAX mixture.

  • You can continue to drink clear liquids until 4 hours before your scheduled arrival time.
  • Do not eat anything until after your procedure.

Things to Remember

  • Take only the medications you were instructed to take the morning of your procedure. Take them with a few sips of water.
  • Do not wear any lotions, creams, or powder to your chest or arms.
  • Remove any jewelry, including body piercings.
  • Leave all valuables, such as credit cards and jewelry, at home. We do not have lockers to store your valuables in.
  • If you wear contacts, wear your glasses instead.

What to Bring

  • Your wallet card, if you have an AICD and your card isn’t already on file with the hospital.
  • Your rescue inhaler (such as albuterol for asthma), if you have one.
  • A case for your glasses or dentures, if you wear them.
  • Your Health Care Proxy form, if you filled one out.

Where to Go

Your procedure will take place at one of these locations:

Endoscopy Suite at Memorial Hospital (MSK’s main hospital)
1275 York Avenue (between East 67th and East 68th Streets)
New York, NY 10065
Take the B elevator to the 2nd floor. Turn right and enter the Surgery and Procedural Center through the glass doors.

MSK’s parking garage is on East 66th Street between York and 1st avenues. If you have any questions about prices, call 212-639-2338.

David H. Koch Center
530 East 74th St.
New York, NY 10021
Take the elevator to the 8th floor.

Paid valet parking is available at the David H. Koch Center for Cancer Care.

MSK Monmouth
480 Red Hill Road
Middletown, NJ 07748

Free parking is available at MSK Monmouth.

What to Expect

Many staff members will ask you to state and spell your name and date of birth. This is for your safety. People with the same or similar names may be having procedures on the same day.

When it’s time to change for your procedure, you will get a hospital gown, robe, and nonskid socks to wear.

You will meet with your doctor before your procedure. They will explain the procedure to you and answer any questions you may have.

You will meet with your anesthesiologist. They will review your medical history with you and talk with you about the kind of anesthesia (medication to make you sleep) you will receive.

A staff member will bring you into the procedure room when it’s time for your colonoscopy. You will lie on your left side with your knees bent.

A healthcare provider will place an intravenous (IV) line into a vein, usually in your arm or hand. You will get anesthesia through your IV, which will make you fall asleep. Once you’re asleep, your doctor will begin the procedure.

Your doctor will place a colonoscope into your rectum. The colonoscope is connected to a video monitor. This lets your doctor see the inside of your colon. Your doctor will use air and fluid to move the colonoscope through your colon while looking for anything unusual on the video monitor.

The procedure usually takes less than 60 minutes (1 hour).

Frequently Asked Questions (FAQs)

I’m taking the prep and started having loose, watery stool before I finished it. Do I still need to take the rest of the prep?

Yes. You must drink all the prep to fully clean out your colon for a safe and complete colonoscopy.

I feel like throwing up (nausea) or did throw up (vomit) after taking the bowel prep. What should I do?

Many people may feel nauseous while drinking the bowel prep. To help with this, try mixing the MiraLAX powder with clear liquids you like drinking.

If you feel like vomiting, you should drink slowly, and take a break. This means you should stop drinking the liquid for 30 to 45 minutes to let your stomach empty. While you take a break, you may put your prep liquid in the refrigerator if you prefer it cold. After your break, try to slowly drink the prep again. Use a straw if you have one.

If you do vomit, take a 30 to 45 minute break. If you have anti-nausea medication at home, you can take 1 dose before starting the prep again. You can drink any clear liquids you like to drink to stay hydrated. It’s important that you drink all the prep liquid to fully clean out your colon for a safe and complete colonoscopy.

After Your Procedure

Your nurse will continue to monitor your heart, breathing, and blood pressure. Many people feel bloated and have stomach cramps after a colonoscopy. This is normal and goes away by passing gas.

Once you’re fully awake, your nurse will remove your IV. If you have someone waiting with you, your nurse will explain your discharge instructions to both of you before you go home.

At Home

  • You may begin eating light foods as soon as you’re discharged. Avoid spicy, greasy, and fried foods at first. Work your way up to your normal diet. If your doctor wants you to limit your diet for a period of time, they will tell you.
  • Do not drink alcoholic beverages for 24 hours after your procedure.
  • You can go back to doing your usual activities 24 hours after your procedure.

If you had a biopsy, it’s normal to have a small amount of bleeding from your rectum. There should not be more than a few drops of blood. The bleeding should stop within 24 hours after your procedure.

After a colonoscopy, it’s normal for your bowel movements to be irregular or different from your usual habits. This may last for up to a week after your procedure.

When to Call Your Healthcare Provider

Call your healthcare provider if you have any of the following:

  • A fever of 101 °F (38.3 °C) or higher.
  • Very bad stomach pain or bloating.
  • Bleeding from your rectum that lasts more than 24 hours.
  • Bleeding between bowel movements.
  • Weakness, faintness, or nausea.
  • Heavy bleeding from your rectum.

Last Updated

Monday, July 17, 2023

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