Constipation in Early Childhood: A Comparative Prevalence Study Between Neurodevelopmentally Disordered and Typically Developing Children

Aims To determine the prevalence of functional constipation (FC) among children aged 1–5 years with typical development (TD) and neurodevelopmental disorders (NDDs), and to identify factors associated with FC. Methods This cross-sectional study was conducted at the general paediatric and developmental clinics at Vajira Hospital between September 2025 and March 2026. A total of 307 children aged 1–5 years were enrolled and categorised into two groups: TD and NDDs. Data were collected using a structured questionnaire and analysed using the Chi-square test, Fisher’s exact test, independent t-test, and univariable and multivariable logistic regression analyses. Interaction analyses were included to assess effect modification. Results Among the 307 children, 51 (16.6%) fulfilled the Rome IV criteria for FC. FC was more common in children with NDDs than in those with TD (26.9% vs 11.3%, p < 0.001). NDDs (adjusted OR [aOR] 2.79, 95% confidence interval [CI]: 1.48–5.26) and a positive family history of constipation (aOR 2.12, 95% CI: 1.06–4.24) were independently associated with FC. Low water intake showed a significant interaction with developmental status ( p = 0.037). Only 60.8% of children with FC were recognised by their caregivers as having constipation. Conclusions FC may be under-recognised in young children, and children with NDDs are a vulnerable population at risk of developing FC. Enhanced clinical awareness and early recognition are essential to facilitate timely diagnosis and appropriate management.