The study at Columbia University's Mailman School of Public Health is based on a large longitudinal survey of Norwegian mothers who were asked about their child's gastrointestinal (GI) disturbances during the first three years of life.
Questionnaires were completed when the children were 18 and 36 months of age.
Researchers found that children with autism spectrum disorder (ASD) had higher odds of their mothers reporting constipation and food allergy/intolerance in the 6- to 18-month-old age range, and higher odds of diarrhoea, constipation, and food allergy/intolerance in the 18- to 36-month-old age range compared to children with typical development.
Children with ASD were more likely to have GI symptoms than children with developmental delay, suggesting that the disturbances were not simply secondary to developmental delay associated with autism.
"We not only learned that these symptoms appeared early in infancy; we also found that children with ASD were at significantly increased risk for these symptoms to persist compared with typically developing children," said Michaeline Bresnahan, first author and assistant professor of Epidemiology at the Mailman School.
Bresnahan added: "GI symptoms alone need not be cause for alarm."
The study is published in the journal JAMA Psychiatry.
