Updated

There's some evidence that fiber supplements may help children with chronic constipation, but little support for other non-drug remedies, a new research review concludes.

The problem, researchers say, is that few rigorous clinical trials have even been done to test non-drug options for children's constipation (that is, treatments other than laxatives and stool softeners).

Their review, published in the journal Pediatrics, was able to find only nine gold standard experiments, known as randomized controlled trials.

In such studies, researchers randomly assign children to either get the therapy being tested or be in a comparison group that receives either no active treatment or a different constipation therapy.
Three of the studies in the review looked at fiber supplements and turned up some evidence that they helped.

One study, which followed 31 children for four weeks, found that dietary fiber supplements seemed to ease stomach pain and boost the number of bowel movements the children had per week. After taking an inactive placebo pill, about half of the kids had infrequent bowel movements (less than three per week). With the fiber, called glucomannan, just one in five kids had problems going to the bathroom.

But the other two studies, which were somewhat larger, failed to find similar benefits.
The rest of the trials tested fluid intake, psychological therapy, probiotics and prebiotics, which are substances that stimulate the growth of good bacteria in the gut. None of the studies produced clear benefits.

But the overall findings need to be "interpreted cautiously," write Dr. Merit M. Tabbers and colleagues at Emma Children's Hospital in Amsterdam.

The studies in the review were generally small, lasted only a few weeks and had other limitations —like having different definitions of chronic constipation. Larger, better-quality studies are still needed, according to the researchers.

Functional constipation—constipation not caused by an underlying medical problem—is a fairly common childhood problem. It's been estimated to affect three percent of children in Western countries at any given time.

So it might seem surprising that there have been so few rigorous clinical trials of treatments for the problem.

There are a number of reasons clinical trials have not been done, Tabbers told Reuters Health in an email, and lack of funding is a prime one. And with some alternative constipation therapies, like massage, it's difficult to "blind" children to whether they are getting the real treatment or not. That blinding is considered a key part of clinical trials.

Tabbers' team found no clinical trials on exercise, massage, homeopathic remedies or acupuncture for treating kids' constipation, even though those tactics are sometimes promoted.
Dr. Carlo Di Lorenzo, chief of pediatric gastroenterology at Nationwide Children's Hospital in Columbus, Ohio, said he wasn't surprised that the existing research has turned up little benefit.
Fiber, for example, simply does not seem to work as well for kids as it does for adults, said Di Lorenzo, who also chairs the American Gastroenterological Association's section on growth, development and aging.

For children, he told Reuters Health, behavior plays a big role in constipation. Once they are constipated, many children become fearful of painful bowel movements, so they "hold it in"—which only worsens the problem.

So teaching kids better bathroom habits is an important and effective part of managing constipation problems, Di Lorenzo said. That, along with eating more fiber-rich fruits, vegetables and grains, and possibly using a stool softener, is enough for many children.

In some cases, Di Lorenzo added, a laxative may be necessary, at least for the short term.
He noted that many parents don't like the idea of giving their child a laxative because they think it creates "dependence."

"But that's a myth," Di Lorenzo said. "The medication does not make you dependent."

He did, however, say that parents should talk with their pediatrician before starting their child on a laxative. Tips from your doctor on behavior changes and diet may make a laxative unnecessary, according to Di Lorenzo.