Osmotic Laxatives

Are osmotic laxatives safe?

Digestive Health Matters 2007;Vol 16 No 2

QUESTION – I would like your opinion on Miralax (PEG 3350 NF powder for solution) available over-the-counter. My doctor recommends this product for daily use. Miralax produces a soft, tubular bowel movement that is messy to clean up. But even more of a concern is that it seems to over-ride the normal thrust of a healthy intestinal tract that pushes fecal matter along. However, the advertisement for Miralax claims it "restores your body's natural rhythm." Do you consider Miralax a safe product for long-term continuous use?

 

ANSWER – Miralax®, and its generic equivalent Glycolax®, is one of several osmotic laxatives that increase water content of the stools in order to treat constipation.  Osmotic laxatives actually make the colon function more effectively without directly stimulating the bowel to be more active.  Thus, they do not override or artificially increase intestinal activity.

The active ingredient in Miralax is polyethylene glycol 3350, which is an inert substance that is absorbed from the intestines in minimal amounts. Several studies and an extensive clinical experience have shown polyethylene glycol containing laxatives to be effective and safe; so convincing are the data that the FDA recently approved it for over-the-counter use by patients without a doctor's prescription.

There is no one best dose, although conventionally it has been given in doses of 17 gm per day.  If the result is a bowel movement that is messy to clean up, try decreasing the amount taken daily in a gradual fashion until you find the daily amount that is best for you.

(Note: As with any drug, read the product label. Ask your healthcare provider or pharmacist if you have questions.)

-- Arnold Wald, MD