Division of Gastroenterology, Hepatology and Nutrition | Miralax and Other Options for Treating Constipation

Functional constipation continues to be a common childhood problem, affecting 3 percent of children worldwide. While not a serious medical condition, functional constipation causes painful bowel movements, abdominal pain, fecal incontinence, and individual and family stress.

To ease the discomfort of chronic childhood constipation, pediatricians often recommend the over-the-counter laxative Miralax (polyethylene glycol 3350.)

The odorless, tasteless powder is typically mixed with 8 ounces of water and prescribed to children once or twice daily. Common side effects include loose bowel movements and sometimes diarrhea, bloating or nausea. These side effects typically improve when dosing is adjusted.

Miralax has lately become a topic of discussion—and scrutiny—among pediatricians, parents and the media because the Food and Drug Administration has not approved it for use in children.

According to the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN), Miralax use appears to be free of serious side effects in most children.

In support of NASPHGAN, Athos Bousvaros, MD, MPH, associate chief of Boston Children’s Hospital's Division of Gastroenterology, Hepatology and Nutrition, notes that Miralax is among the best-studied medications for childhood constipation and that studies suggest it is both safe and effective.

Miralax has been very well studied, probably more closely than any other medication over the past 15 years,” he says.

Miralax is one of many options for treating childhood constipation. The first line of defense when managing functional constipation is lifestyle modification, such as increased hydration, high-fiber diets and regular exercise prior to introducing Miralax or other forms of treatment.”

When lifestyle modifications have been exhausted, medication options for treating constipation include:

  • Miralax
  • lactulose (a non-absorbable sugar)
  • magnesium hydroxide (aka Milk of Magnesia)
  • senna (an herbal extract that stimulates bowel motions)
  • mineral oil 

It is important for clinicians to stress to parents and caregivers that these products should ONLY be used at the recommendation of a trained health care provider. Also, many pediatricians and gastroenterologists have moved away from prescribing mineral oil because of an increased risk of aspiration and of fat-soluble vitamin deficiency prompted by its use.

Evidence-based guidelines

To assist health care workers in the management of childhood constipation in primary, secondary and tertiary care, NASPGHAN and ESPGHAN (European Society for Paediatric Gastroenterology, Hepatology, and Nutrition) elected to develop evidence-based guidelines as a joint effort. 

The present guidelines—available here and co-authored by Samuel Nurko, MD, MPH, director of Boston Children’s Center for Motility and Functional Gastrointestinal Disorders—provide recommendations for the diagnostic evaluation of children presenting with constipation and the treatment of children with functional constipation. 

These guidelines should not be considered a substitute for clinical judgment or as a protocol applicable to all patients. They also are not aimed at the management of patients with underlying medical conditions causing constipation, but rather just for functional constipation.

If you have questions about the care of patients with constipation, contact Boston Children's Division of Gastroenterology, Hepatology and Nutrition.