Autism spectrum disorders (ASDs) are a set of complex neurodevelopmental disorders defined behaviorally by impaired social interaction, delayed and disordered language, repetitive or stereotypic behavior, and a restricted range of interests. ASDs represent a significant public health issue with recent estimates indicating that as many as 1% of children in the United States are diagnosed with an ASD.1,2 Many individuals with ASDs have symptoms of associated medical conditions, including seizures, sleep problems, metabolic conditions, and gastrointestinal (GI) disorders, which have significant health, developmental, social, and educational impacts. Gastrointestinal complaints are a commonly reported concern for parents and may be related to problem behaviors and other medical issues such as dysregulated sleep (ATN Annual Registry Report, unpublished data, November 2009).3 Despite the magnitude of these issues, potential GI problems are not routinely considered in ASD evaluations. This likely reflects several factors, including variability in reported rates of GI disorders, controversies regarding the relationship between GI symptoms and the putative causes of autism, the limited verbal capacity of many ASD patients, and the lack of recognition by clinicians that certain behavioral manifestations in children with ASDs are indicators of GI problems (eg, pain, discomfort, or nausea).4–10
Whether GI issues in this population are directly related to the pathophysiology of autism, or are strictly a comorbid condition of ASD remains to be determined, but clinical practice and research to date indicate the important role of GI conditions in ASDs and their impact on children as well as their parents and clinicians.9
On November 15, 2009, a symposium addressing these issues was organized as an adjunct to the annual meeting of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition. A panel of international experts presented the latest scientific information on pathophysiology, evaluation, and treatment strategies for GI conditions in children and adolescents with ASDs. One aim of the meeting was to raise awareness among gastroenterologists and GI researchers of GI disorders in the ASD population and to provide clinicians with information to improve their clinical practice for these children. The symposium addressed 4 major areas of concern for children with ASDs: reflux, constipation, diarrhea, and nutrition. Each session reviewed the state of the evidence, the latest findings on issues such as intestinal permeability, inflammatory processes, innervation, motility, nutrition, and the epidemiology, presentation, and clinical management of GI issues.
The symposium also set the context for a follow-up workshop on November 16 that focused on identifying and prioritizing the key research topics for further investigation. The 1-day workshop brought together a group of symposium participants and speakers with a broad range of expertise in GI and autism clinical practice, and clinical as well as basic science research.
This report provides an overview of findings in GI and ASDs as presented in the symposium and highlights the key conclusions from the workshop. Specifically, the group identified the following 4 topics as priority areas for further study: epidemiology of GI conditions in ASDs, underlying pathology (gut-brain connection, immune function, animal models and genome-microbiome interaction), treatment and outcome, and nutrition. A recent consensus report on GI conditions in ASDs published in Pediatrics in 20109put forth 23 recommendations for the evaluation and management of GI conditions in ASDs. Although ASDs are behaviorally defined disorders, current thinking suggests multiple “autisms” with varying biological underpinnings. Some of these may eventually be identified as having associated GI symptoms, as has been seen with the MET gene. Pending new evidence on any such relationships, the recommendations in this current article expand upon several of the key recommendations made in the consensus statement highlighting areas in need of new knowledge.