Background: Gastrointestinal (GI) disorders are common in autism spectrum disorder (ASD). Infant colic (IC), the functional GI disorder of infancy, has not been evaluated in this patient group. The aim of this study was therefore to determine the rate of IC in ASD and investigate a possible association between ASD and IC.
Methods: The subjects consisted of 100 ASD patients (mean age, 6.6 ± 3.5 years) and 100 healthy controls (mean age, 5.3 ± 2.8 years). The parents were questioned using the diagnostic criteria for infant colic for clinical research purposes defined in Rome IV to diagnose IC, retrospectively. The sample size was estimated using a maximum type I error probability of 5% (alpha) and a type II error of 20%.
Results: The rate of IC was 16% and 17% in the ASD group and control group, respectively (P ˃ 0.05). Excessive crying with late onset and long duration in infants was defined as persistent crying. The rate of persistent crying was significantly higher in the ASD group than in the control group (32% vs 9%, P < 0.001). The relative risk of persistent crying was 4.40 in ASD. The likelihood of being misdiagnosed with IC in this group was 78%.
Conclusion: The rate of IC is not increased in patients with ASD, but infants with excessive crying should be very thoroughly evaluated before being diagnosed with IC. In particular, persistent crying in infants (i.e. excessive crying with late onset and long duration) may be an early symptom of ASD.
Keywords: autism spectrum disorder; gastrointestinal; infant colic.
© 2018 Japan Pediatric Society.