Brief Report: Association Between Autism Spectrum Disorder, Gastrointestinal Problems and Perinatal Risk Factors Within Sibling Pairs.

Isaksson et al. (2017) looked at sibling pairs where only one child had autism. They asked moms about tummy trouble and about birth events like jaundice or low birth weight.

The team wanted to know: do GI problems stick with the ASD child even after we remove shared womb risks?

The ASD child still had more stomach pain, diarrhea, and constipation than the brother or sister. Shared birth risks did not wash out the GI link.

This hints that something outside the womb drives the gut trouble in ASD.

Lee et al. (2018) later showed the same GI–ASD link in a full population, not just brothers and sisters. The pattern holds beyond the family kitchen table.

Bottema-Beutel et al. (2023) added a twist: gut pain and anxiety chase each other over time. Treat one and you may calm the other.

Kaiser et al. (2022) pooled many studies and found kids with ASD are about 1.5 times more likely to get inflammatory bowel disease. The sibling data now sit inside that bigger picture.

When a child with ASD complains of belly pain, do not brush it off as “just behavior.” Track food, stool, and mood daily. Share the log with the pediatrician. A simple diet tweak or GI referral can cut problem behavior that stems from hidden gut pain.