Gastrointestinal dysfunction in autism: parental report, clinical evaluation, and associated factors

Abstract

The objectives of this study were to characterize gastrointestinal dysfunction (GID) in autism spectrum disorder (ASD), to examine parental reports of GID relative to evaluations by pediatric gastroenterologists, and to explore factors associated with GID in ASD. One hundred twenty-one children were recruited into three groups: co-occurring ASD and GID, ASD without GID, and GID without ASD. A pediatric gastroenterologist evaluated both GID groups. Parents in all three groups completed questionnaires about their child's behavior and GI symptoms, and a dietary journal. Functional constipation was the most common type of GID in children with ASD (85.0%). Parental report of any GID was highly concordant with a clinical diagnosis of any GID (92.1%). Presence of GID in children with ASD was not associated with distinct dietary habits or medication status. Odds of constipation were associated with younger age, increased social impairment, and lack of expressive language (adjusted odds ratio in nonverbal children: 11.98, 95% confidence interval 2.54-56.57). This study validates parental concerns for GID in children with ASD, as parents were sensitive to the existence, although not necessarily the nature, of GID. The strong association between constipation and language impairment highlights the need for vigilance by health-care providers to detect and treat GID in children with ASD. Medications and diet, commonly thought to contribute to GID in ASD, were not associated with GID status. These findings are consistent with a hypothesis that GID in ASD represents pleiotropic expression of genetic risk factors.

Figure 1. Gastrointestinal Dysfunction in Children With and Without ASD, by Physician’s Evaluation and Parent’s Report

Diagnoses of gastrointestinal dysfunction, by both a pediatric gastroenterologist’s clinical evaluation and a parent’s report on a symptom-based classification instrument, for children with and without ASD. Constipation was the most prevalent diagnosis, and concordance between parents and clinicians was fair to moderate for a specific diagnosis of constipation, but high when considering presence versus absence of any gastrointestinal dysfunction.

Figure 2. Social Impairment Measured by SRS T-Scores

Social impairment, measured on the Social Responsiveness Scale, was significantly greater in both ASD groups, compared to the GID-only group; the most social impairment was seen in the ASD-GID group.

Figure 3. Percent of Food Categories Eaten During Seven Days

Parents recorded foods eaten by their children for seven days, in 11 different food categories. Relative distributions of food categories eaten did not differ significantly across any of the three groups.