More Than Discomfort: How Gastrointestinal Symptoms Affect Children with Autism

Children with autism experience significantly more gastrointestinal problems than children without autism, and these symptoms tend to persist throughout childhood. Furthermore, the more digestive symptoms appear, the greater the difficulties with sleep, communication, sensory sensitivity, and behavior. Identifying and treating these symptoms can bring significant benefits to the well-being of these children.

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by difficulties with social communication and the presence of restricted and repetitive behavior patterns. In the United States, it is estimated that approximately 1 in 36 children is diagnosed with autism.

In addition to the core features of the disorder, these children often present with other health problems, such as sleep disturbances, seizures, and gastrointestinal symptoms (GI).

Although there is still no consensus on the exact prevalence of these gastrointestinal symptoms, they are among the most common medical complaints reported by families of children with autism.

Studies show that these symptoms occur much more frequently in autistic children than in typically developing children, although the reported rate varies widely across studies, from 4.2% to nearly 97%, with a median around 47%.

Often, these problems are not linked to a specific gastrointestinal diagnosis or a known medical condition. Yet, if left untreated, they can worsen other aspects of a child's development and increase the risk of hospitalizations. 

Previous research has suggested that gastrointestinal symptoms, such as abdominal pain or constipation, may be linked to the emergence or worsening of challenging behaviors, including aggressive outbursts, self-injury, and difficulty sleeping or maintaining attention.

In a previous study conducted by the same team, it was observed that nearly half of children aged 2 to 3 with autism had gastrointestinal symptoms, and that the presence of these symptoms was directly associated with self-injurious behaviors, sleep problems, and increased agitation.

The relationship between autism and gastrointestinal problems is still not fully understood. Some researchers suggest that these symptoms are linked to food selectivity common in children with ASD—a diet that is highly restricted or limited to certain foods, which can lead to nutritional imbalances.

Other possible factors include sensory selectivity (when the child rejects the textures, smells, or tastes of certain foods), rigidity in following specific mealtime routines, and limited eating patterns.

Furthermore, social communication difficulties can interfere with how a child expresses physical discomfort, influencing their perception of and response to symptoms. There are also hypotheses linking gastrointestinal symptoms to the gut-microbiota-brain axis, via the enteric nervous system, which opens the door to further research in this area.

Despite the relevance of the topic, few studies have investigated how these symptoms evolve over time in children with autism. Some studies have monitored the presence of gastrointestinal symptoms over short periods, such as one or two years, and have shown that symptoms tend to persist.

Other studies have retrospectively analyzed medical records and found no clear differences between children and adults with or without autism, but faced significant methodological limitations, such as a lack of consistent data collection criteria. These limitations hinder generalization of the results and highlight the need for more comprehensive prospective studies.

Consequently, the current study sought to fill this gap. Researchers at the University of California, USA, conducted a longitudinal follow-up study to assess the frequency and persistence of gastrointestinal symptoms in children with autism throughout childhood, comparing the results with a group of children diagnosed with attention deficit disorder (ADD).

The study was based on a well-characterized sample, assessed at different points in childhood, using standardized measures of both development and behavior.

The primary hypotheses were: first, that children with autism would present with more frequent and persistent gastrointestinal symptoms than children with ADHD; and second, that the presence of gastrointestinal symptoms would be associated with greater difficulties in several behavioral domains throughout childhood, including social communication, sleep, repetitive behavior, and attention.

A total of 475 children enrolled in this longitudinal study (322 with autism spectrum disorder and 153 with typical development) were assessed at up to three time points between the ages of 2 and 12. Nine common gastrointestinal symptoms and a formal medical gastrointestinal diagnosis were assessed through a parent interview administered by a physician.

Symptoms were rigorously classified by physicians using clinical consensus. The frequency and persistence of gastrointestinal symptoms throughout childhood were compared between groups.

Associations between gastrointestinal symptoms and measures of internalizing and externalizing behaviors, sleep problems, sensory problems, restricted and repetitive behaviors, and social communication were also assessed.

Percentage of participants with ASD and TD who never reported gastrointestinal symptoms or reported them once, twice, or three times.

Children with autism presented more gastrointestinal symptoms at each time point and were also more likely to have multiple and persistent gastrointestinal symptoms. The presence and number of gastrointestinal symptoms were associated with greater impairment in internalizing behaviors, sleep, communication, sensory processing, and repetitive behaviors.

Participants in the autism spectrum disorder group reported more gastrointestinal symptoms with no known etiology throughout childhood in this well-characterized longitudinal sample.

Clinicians and parents should be more aware of the high incidence of gastrointestinal problems in children with autism. If identified, these symptoms are often treatable, which can improve their well-being.

READ MORE:

A longitudinal evaluation of gastrointestinal symptoms in children with autism spectrum disorder. 

Restrepo, B., Taylor, S. L., Dominic Ponzini, M., Angkustsiri, K., Solomon, M., Rogers, S. J., Ashwood, P., Say, D. S., Caceres, S., Alavynejad, S., Heath, B., Amaral, D. G., and Wu Nordahl, C. 

Autism. August 28, 2025

https://doi.org/10.1177/13623613251362349

Abstract: 

Gastrointestinal symptoms are frequently reported in children diagnosed with autism spectrum disorder. This study sought to determine the longitudinal trajectory of gastrointestinal symptoms without a medical etiology in children with autism compared to similar aged participants with typical development. A total of 475 children enrolled in this longitudinal study (322 autism spectrum disorder and 153 typical development groups) were evaluated at up to three time points between 2 and 12 years of age. Nine common gastrointestinal symptoms and formal medical gastrointestinal diagnosis were assessed using a physician-administered parent interview. A rigorous symptom classification was performed by physicians via clinical consensus. The frequency and persistence of gastrointestinal symptoms across childhood were compared between groups. Associations between gastrointestinal symptoms and measures of internalizing and externalizing behaviors, sleep problems, sensory problems, restricted and repetitive behaviors, and social communication were also evaluated. Children with autism presented with more gastrointestinal symptoms at each time point, and they were also more likely to experience multiple and persistent gastrointestinal symptoms. The presence and number of gastrointestinal symptoms were associated with greater impairment in internalizing behaviors, sleep, communication, sensory processing, and repetitive behaviors. Participants in the autism spectrum disorder group reported more gastrointestinal symptoms without known etiology throughout childhood in this longitudinal well-characterized sample.