Stomach condition may have strong link to autism in children
In this DML Report…
A University of California, Davis study tracked gastrointestinal symptoms in 475 children over nearly a decade, including 322 diagnosed with autism spectrum disorder (ASD) and 153 neurotypical children, as part of the UC Davis MIND Institute Autism Phenome Project. Caregivers completed questionnaires at three intervals—baseline ages two to four, follow-up ages four to six, and middle childhood ages nine to 12—rating symptom frequency from never to always for issues like abdominal pain, gas, diarrhea, bloating, constipation, pain during bowel movements, vomiting, difficulty swallowing, blood in stool, and blood in vomit. Children reporting at least one symptom in the prior three months were classified as having gastrointestinal symptoms (GIS). Among ASD participants, 43 reported food allergies, and gastroesophageal reflux disease (GERD) emerged as the most common formally diagnosed digestive condition. The research, published in August in the journal Autism, aimed to assess GIS persistence and development in relation to autism.
At baseline, 47 percent of ASD children reported GIS compared to 30 percent of neurotypical children, a 44 percent higher likelihood for those with autism; by the second evaluation, figures were 40 percent versus 15 percent, a 91 percent difference; and at the third, 30 percent versus 7 percent, exceeding a four-fold disparity. Overall, 61 percent of neurotypical children never experienced GIS, versus 34.5 percent of ASD children, a 55 percent gap, with autistic children twice as likely to develop symptoms over time. Constipation affected 32 percent of ASD children versus 11 percent of neurotypical peers, abdominal pain 17 percent versus 12 percent, and diarrhea 27 percent versus 11 percent; each symptom proved more prevalent in the ASD group. Probability models showed GIS risk rising more sharply with age among autistic children.
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GIS in ASD children correlated with heightened autism-related behaviors, including repetitive actions, anxiety, depression, aggression, defiance, social difficulties, and sleep disturbances. Prior studies link these issues to restrictive diets in autistic children—often fried, low-fiber, highly processed "safe" foods—and potential gut bacteria imbalances. In the U.S., autism diagnoses affect one in 31 children, up from one in 150 in the early 2000s. Senior author Dr. Christine Wu Nordahl, principal investigator at the UC Davis MIND Institute, stated: "This is not about finding a single cause. It's about recognizing the whole child. Supporting gastrointestinal health is one important step toward improving overall quality of life for children with autism." Researchers recommend routine GIS screening to address underlying problems, particularly in children with communication barriers, and call for further studies on symptom trajectories throughout childhood.