Autism Study Links Bowel Symptoms and Rigid, Repetitive Behaviors

Date: 
December 10, 2013
Raises possibility that relieving constipation could ease some autism symptoms; GI and rigid behaviors may share common cause

In recent years, research has supported parent reports that many children with autism struggle with chronic constipation. A new study goes one step further and associates severe constipation in children with autism with rigid and repetitive behaviors. It appears online in the Journal of Autism and Developmental Disorders.

The researchers delved into the wealth of anonymous information provided by families who voluntarily participate in the patient registry of the Autism Speaks Autism Treatment Network (AS-ATN). (Read more about this network of 17 autism-focused medical centers here.)

Specifically, they looked at children who experience severe constipation that alternates with periods of diarrhea or stool leakage – a pattern often seen by gastroenterologists who care for patients with autism. The investigators found that children with these GI symptoms were more likely to have difficulties with repetitive or compulsive behaviors, as reported by their parents. This was in comparison to children with autism but no chronic constipation.

“Our findings add support to the conclusion that children with both autism and GI disturbances are at greater risk for severely disruptive, autism-related behaviors,” says study co-author Pat Levitt, of Children's Hospital Los Angeles. The study also involved investigators at Vanderbilt University Medical School and Nationwide Children’s Hospital. All three medical centers are part of the AS-ATN.

The findings also support anecdotal reports from parents and autism GI specialists that relieving bowel problems can increase the benefits of behavioral therapies, according to Autism Speaks Chief Science Officer Rob Ring. “If you can identify and treat the GI symptoms, then you may improve the effectiveness of interventions by increasing a child’s ability to pay attention and cooperate with the therapist,” Dr. Ring says.

Further study needed to determine cause and effect
The researchers offered several possible explanations for the association they found. Constipation-related discomfort could be worsening the children’s repetitive behaviors. Conversely, rigid behaviors could worsen constipation by interfering with normal toileting. Third, there could be a common biological cause for both constipation and compulsive behaviors. The investigators noted earlier research – involving Autism Speaks Autism Genetic Resource Exchange – that supported the latter possibility. It associated certain autism-linked genes with the presence of severe GI symptoms. 

"The Autism Speaks Autism Treatment Network is a wonderful resource for autism research because it allows us to take an observation from the clinic and quickly check it in a large population,” says co-investigator Jeremy Veenstra-VanderWeele of Vanderbilt University Medical School. “The association between these symptoms is strong,” Dr. Veenstra-VanderWeele adds. “But we need to do further research to understand the underlying cause." 

For more information and resources, see Autism Speaks ATN/AIR-P Guide for Managing Constipation in Children (available for free download) and “GI Distress and Autism: Q&A with Pediatric Gastroenterologist Tim Buie.

To find an AS-ATN center in your region, click here.