Skip navigation

Calls to Action

Researchers Scrutinizing Safety of Laxative Used by Many with Autism

FDA funds study to investigate concerns about long-term use of Miralax, used daily by many affected by autism and chronic constipation
January 06, 2015

The Food and Drug Administration has asked researchers to look more closely at children’s long-term use of Miralax and related laxatives containing the active ingredient polyethylene glycol. The potential safety issues are of particular concern for the autism community as many children – and adults – affected by the disorder suffer from chronic constipation.

Polyethylene glycol works by drawing water into the colon to soften stool. It’s FDA-approved for short-term use by adults (up to seven days at a time). However, many doctors have long recommended it for daily use in children with chronic constipation, based on the belief that very little is absorbed into the body.

Yet the FDA has received reports of tremors, tics and obsessive-compulsive behavior in children given laxatives containing polyethylene glycol. The new study will investigate whether the chemical or product contaminants may be the cause.

“It’s been my contention for a long time that we don’t know how safe this product is,” comments pediatric gastroenterologist Timothy Buie, director of GI and nutritional services at the Lurie Center for Autism at MassGeneral Hospital in Boston. The Lurie Center is part of Autism Speaks Autism Treatment Network (ATN). “I’ve never been an advocate for its long-term use and try very hard to look for alternatives.” In training new doctors, Dr. Buie says he emphasizes a creative and collaborative approach when managing chronic GI problems such as constipation. “Chronic problems need a creative working through of diet and lifestyle in ways that minimize the reliance on medicines,” he says. Dr. Buie also has concerns about Senna and other herbal laxatives that many parents turn to as alternatives.

Look for Dr. Buie’s “Office Hours” video segments and Q&A’s on the management of GI issues associated with autism, Wednesdays throughout January at

“Hopefully studies such as this will further spur us to look at probiotics and other safer alternatives to managing chronic constipation,” Dr. Buie adds. Through its “Gut-Brain Research Initiative,” Autism Speaks is currently funding research on probiotics and chronic constipation in children with autism. Read more about this research here.

The new FDA-funded study will be led by gastroenterologists Robert Heuckeroth and Ritu Verma of the Children’s Hospital of Philadelphia. Dr. Verma and the hospital are likewise part of the Autism Speaks ATN.

Their study will investigate how children’s bodies break down or otherwise metabolize polyethylene glycol and the potentially toxic contaminants that result from the chemical’s manufacture.

According to the FDA’s brief to the researchers, the agency found trace amounts of ethylene glycol and diethylene glycol in the batches of Miralax that it had tested. Trace amounts of these potentially toxic manufacturing contaminants are allowed. But their presence raises concerns when a product is used long term.

“There are many, many unknowns about the treatment of constipation in children, which is why Autism Speaks is sponsoring rigorous research in this area,” says developmental pediatrician Paul Wang, Autism Speaks head of medical research. “We are glad to be aligned with Dr. Verma as one of our ATN doctors and a leader in this area.”

Read the full New York Times story here.