Constipation outcomes in children with and without autism spectrum disorder: Insights from a tertiary motility service

OBJECTIVES: Autism spectrum disorder (ASD) is commonly associated with gastrointestinal comorbidities, particularly chronic constipation. Despite high clinical burden and frequent tertiary referrals, comparative data describing clinical characteristics, management and outcomes between children with and without ASD-and across ASD severity levels-remain limited. This study compared constipation outcomes at 1 year and the most recent follow-up between children with and without ASD and assessed whether autism severity influenced prognosis. METHODS: We retrospectively analysed children with chronic constipation managed through a tertiary motility service and enrolled as of 31 January 2024. Demographics, comorbidities, adherence, interventions and outcomes were extracted. Subgroup analyses examined outcomes across ASD severity levels. Statistical comparisons used Chi-square, Mann-Whitney U and Kruskal-Wallis tests, with significance defined as p < 0.05. RESULTS: Among 196 children, 74 (37.7%) had ASD and 122 (62.2%) did not. The ASD cohort had more males (62.2% vs. 45.9%, p = 0.038), lower medication adherence (56.8% vs. 76.2%, p = 0.006) and lower constipation resolution at last follow-up (11% vs. 25%, p = 0.036). Attention deficit hyperactivity disorder (ADHD) was more prevalent in the ASD group (50% vs. 13.9%, p = 0.0001). Across ASD severity levels, outcomes, compliance, and therapy needs were broadly similar, though toileting compliance tended to be lowest in Level 3. CONCLUSIONS: Children with ASD demonstrate lower treatment adherence and poorer constipation resolution compared with non-ASD peers. Outcomes across ASD severity levels are largely similar. Targeted, multidisciplinary strategies are needed to address adherence and optimise outcomes in this high-risk group.