Polyethylene Glycol


In this session we will be discussing the consumer medication information for polyethylene glycol, trade name MiralaxTM.

What it’s for & How to take

Polyethylene glycol is an osmotic laxative that is used to treat constipation. This medication increases water retention in the stool which results in a softer stool and more frequent bowel movements. This medication appears to have little or no effect on the absorption of electrolytes from the gastrointestinal tract.

Polyethylene glycol is available as both a prescription and over-the-counter medication. The strength of the medication is the same. The difference is, over-the-counter polyethylene glycol is for the occasional treatment of constipation and is not to be used on a regular basis. When using the over-the-counter form of polyethylene glycol, read the instructions on the label, so you know when you need to consult your pharmacist or doctor for follow-up treatment instructions.

Polyethylene glycol is usually used once daily or as directed by your doctor. This medication is available in both pre-measured packets and a bulk bottle. When using the bulk bottle, the cap of the bottle is used as the measuring device.

Mix your dose of polyethylene glycol in 4-8 ounces of fluid such as water or juice. Stir the solution until all the powder has dissolved in the liquid before drinking the mixture. It may take up to 4 days of daily dosing before you experience a bowel movement. Do not increase your dose or take it more frequently unless directed to do so by your doctor.

If your doctor has prescribed you to take this medication daily and you miss a dose, take it as soon as you remember. If it is near the time of your next dose, skip it and continue with your normal dose time. Do not take a double dose to make up the missed dose.

Warnings & Cautions

  • Unless directed by your doctor, do not use this medication for more than 14 days in a row. It is possible that overuse of polyethylene glycol may result in dependence upon laxatives, chronic constipation, diarrhea, dehydration or possibly an electrolyte imbalance.
  • The elderly may be much more sensitive to the side effects of this medication, especially diarrhea.
  • If you have recently experienced acute abdominal pain, nausea or vomiting, contact your health care provider before using this medication.
  • Let your pharmacist or doctor know if you are pregnant or breastfeeding before taking this medication.
  • Consult your pharmacist or doctor before giving a dose of this medication to your child.

Interactions & Side Effects

  • Tell your pharmacist or doctor all your medication allergies so they may determine if polyethylene glycol is safe for you to take.
  • Avoid dangerous drug interactions. Tell your pharmacist or doctor all the other medication you are taking, including over the counter supplements, even if you don’t take them very often.
  • Ask your doctor if this medication is safe to take with your current health conditions. Tell your doctor if you have a history of kidney disease, persistent nausea, vomiting or abdominal pain, or any sudden changes in bowel habits over the past 2 weeks. This medication is not to be used if a bowel obstruction is present.
  • While taking polyethylene glycol, you may feel some excess gas, nausea, cramping or diarrhea. If these or any other unwanted side effects persist, contact your doctor or pharmacist to talk about it with them.
  • Call your doctor right away if you have any persistent diarrhea, blood in your stool or severe or worsening abdominal pain.

If you have any questions about what you have heard, contact your pharmacist or doctor. This session does not include all the potential interactions or side effects that this medication may cause. Ask your pharmacist how your medication should be stored and how you should dispose of it when you are done taking it. Do not share your medication with anyone, ever. Remember, this is not meant to replace your counseling session with your pharmacist. In case of overdose, call your local poison control center at 1-800-222-1222.

Updated 7/20