Many parents of children with autism report gastrointestinal (GI) pain in their child, but the question remains whether the association between autism and bowel disease truly exists.
An editorial published Thursday in the British Medical Journal examined the continued belief by many of a possible connection between the developmental disorder and the chronic inflammatory bowel disease, that was first dubbed "autistic enterocolitis" by British physician Dr. Andrew Wakefield.
But beyond Wakefield's account, the evidence of any connection between bowel disease and autism is slim, the editorial stated.
The hypothesis was first introduced in 1998 in a roundly discredited study by Wakefield. His paper, published in The Lancet, tied autism and bowel disease to the measles vaccine.
Critics accused Wakefield's paper of using fabricated data to find a link between receipt of the MMR vaccine and the onset of what he described as "behavioral symptoms." And although the paper was retracted from the journal, the belief remained among some doctors and many parents.
According to Dr. Stefani Hines, a development-behavioral pediatrician at William Beaumont children's hospital in Royal Oak, Mich., the belief is so deep rooted in the autism community that many parents ask her if alleviating their child's stomach pains will treat their autism.
A panel report published in the January issue of Pediatrics found no evidence that digestive problems are more common in children with autism compared to other children, or that special diets -- including the popular gluten-free casein-free diet -- work.
But according to some experts, for a child who has significant behavioral and communication disabilities, it may be difficult for the child to communicate GI issues. And, experts said, the persisting pain from gastrointestinal problems can trigger behavior problems in children with autism.
However, regardless of the evidence, popular belief resides among many experts and parents alike that eliminating certain foods that could cause gastrointestinal problems may help to reduce behavioral problems, a common symptom found in autistic children.
Diets have been promoted by celebrities like Jenny McCarthy, whose best-selling book, "Louder Than Words," detailed her use of diets as one method to treat her autistic son. And many autism communities have touted the purported benefits of specialized diets for their children.
Diane Marshall, 42, of Montclair, N.J. put her son David, 13, on a gluten-free casein-free (GFCF) diet for a year when he was 4-years-old. Marshall said that she read success stories from some mothers who tried the diet for their autistic children. At the time, David suffered with severe eczema and a runny stool, she said.
"We definitely thought the diet would help the autism," said Marshall. "We thought [the diet would] get rid of the G.I. issues and also get rid of the autism symptoms."
While the GI issues subsided, Marshall said she did not attribute the end of her son's stomach problems to the diet. And, she said the diet did not help her son overcome autism.
"There are a lot of things out there that are based on evidence, like teaching methods, that will help our kids a lot, but not diets," said Marshall.
According to Dr. Daniel Coury, medical director of the Autism Treatment Network, about 20 percent of parents within the Autism Treatment Network use complementary methods to treat their autistic child, and more than half of those use some form of diets.
"Clearly the gluten free diet is successful in those with celiac disease, but there is no consistent pattern in children with autism," said Coury.
According to Hines, many parents of autistic children hear about diets so often through the autism community that, regardless of the lack of evidence, they are compelled to try it.
"I do caution that the [GFCF] diet can lack in calcium and protein so I suggest [that parents] meet with a nutritionist," said Hines. "If the diet has helped you, then do what you need to do, but really there's nothing supporting any recommendation to use it for children with autism."
While Marshall said she did not see the value in the diet for her son's autism, many parents like herself are likely to try treatments they've been told worked for other autistic children.
"I've been there; you want to try anything and everything for your kid to make sure you've done your best, so I can understand people wanting to give it a try," said Marshall. "But I don't think you should put all your eggs in one basket. It is not a cure for autism."
According to Coury although many children in general suffer from gastrointestinal problems, children with autism are less likely to be treated than those without the disorder.
"Some physicians assume that GI complaints are part in parcel with the child having autism, and so they say nothing can be done," said Coury. "But if those complaints are with a typical child, then proper medical attention is sought."
The same treatment that is offered to children without autism who suffer from GI issues should be given to those with autism, he said. For some autistic children in some instances, spontaneous movements may be a reaction to gastrointestinal pain.
"We might miss that with children on the spectrum because we attribute these behaviors to autism rather than GI reflux," said Coury.
"We know that gastrointestinal symptoms exist across the entire pediatric population," said Hines. "When some of these non-verbal autistic children have pain, they may not be able to tell you what is experienced among all children."
But while current research does not suggest a link between autism and bowel disease, according to Coury, improving the GI problems could help improve an autistic child's overall health.
"If we improve your health, and you feel better, you're more available to learn in school, you're more available to make improvement in your development," said Coury. "So we think improvement in health may help the child make better progress in their autism."