To prospectively assess the prevalence of autism spectrum disorder (ASD) symptoms in children presenting with functional defecation disorders.

Children (age 4-12 years) with functional constipation or functional non-retentive fecal incontinence according to the Rome III criteria referred to a specialized outpatient clinic were included. Parents completed 2 validated ASD screening questionnaires about their child; the Social Responsiveness Scale (SRS) and the Social Communication Questionnaire-Lifetime (SCQ-L). A total SRS score of ≥51 is a strong indicator for the presence of ASD. On the SCQ-L, a score of ≥15 is suggestive for ASD.

In total, 242 patients (130 males, median age 7.9 years) were included. Of these, 91% were diagnosed with functional constipation and 9% with functional non-retentive fecal incontinence. Thirteen children (5.4%) had previously been diagnosed with ASD. Twenty-six children (11%) had both SRS and SCQ-L scores at or above cutoff points, strongly suggestive for the presence of ASD. Solely high SRS were present in 42 children (17%), whereas two children (1%) only had high SCQ-L scores. Altogether, 29% had ASD symptoms, indicated by SRS and/or SCQ-L scores at or above the cutoff values. These children were older than children without ASD symptoms and presented with a longer duration of symptoms.

A substantial number of children (29%) presenting with a functional defecation disorder at a tertiary hospital has concomitant ASD symptoms. Clinicians should be aware of ASD symptoms in children with functional defecation disorders.