Autism and the Gut: GI Symptoms and Behavior

Many children with autism experience stomach and digestion challenges that can affect their daily lives. A new study shows these gastrointestinal (GI) issues are not only more common in autism, but they often last through childhood and connect to sleep, behavior, and learning. Understanding the link between autism and the gut can help parents, educators, and therapists better support children at home and school.

Why the Gut Matters in Autism

Many children with autism experience medical challenges alongside their learning and social differences. One area that researchers have paid attention to is the gut. Gastrointestinal (GI) symptoms—such as constipation, diarrhea, bloating, or stomach pain, are reported more often in children with autism than in their typically developing peers.

The study by Restrepo and colleagues (2025) followed 475 children between ages 2 and 12, including both children with autism and children with typical development. The researchers wanted to understand how GI symptoms appear and persist over time, and whether these symptoms are connected to other challenges like sleep or behavior.

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What the Study Found on Autism and the Gut

GI Symptoms Are More Common in Autism

The study followed 322 children with autism and 153 children with typical development. Across every age group (from preschool through middle school), children with autism were about twice as likely to experience gastrointestinal (GI) symptoms as their peers without autism. The researchers calculated a relative risk (RR) of 2.04, meaning children with autism were more than twice as likely to report issues like constipation, diarrhea, or abdominal pain.

Interestingly, girls with autism had slightly higher rates of GI symptoms than boys, though this difference was not statistically strong enough to be conclusive.

Symptoms Persist Over Time

GI challenges weren’t just one-time events. They tended to stick around through childhood.

  • About half of the children with autism had GI issues at two or more different ages during the study.
  • Around 30 percent of children with autism had symptoms across all three time points (ages 2–4, 4–6, and 9–12 years).
  • In contrast, only about 7 percent of typically developing children had persistent symptoms across all three stages.

This persistence suggests that for many children with autism, GI problems are ongoing rather than temporary.

Common Symptoms

The most frequent GI symptoms in autism were:

  • Constipation (32 percent)
  • Diarrhea (27 percent)
  • Gas and bloating (27 percent)
  • Abdominal pain (17 percent)restrepo-et-al-2025-a-longitudi…

Other symptoms, such as pain with stooling, vomiting, or difficulty swallowing, were reported but were less common.

Linked to Behavior and Well-Being

One of the most important findings was how strongly GI symptoms were tied to other areas of daily life. Children with autism who had GI issues showed:

  • More sleep problems, including bedtime resistance, night waking, parasomnias (such as sleepwalking or night terrors), and daytime sleepiness
  • More anxiety and internalizing behaviors, such as being withdrawn or emotionally reactive
  • Greater sensory sensitivities, especially to sound, touch, taste, and smell
  • More repetitive behaviors and difficulties with social communication.

In fact, the more GI symptoms a child experienced at the same time, the greater the impact on these areas. Children with multiple ongoing GI problems showed higher levels of challenges across 22 different behavioral measures.

Why Autism and the Gut Research Matters for Families and Schools

GI problems are not always obvious, especially since many children with autism may struggle to communicate discomfort. Instead, pain or discomfort may show up as increased irritability, sleep problems, or changes in behavior. This means:

  • Families should share concerns about digestion or bowel habits with their child’s healthcare provider.
  • Teachers and therapists should consider whether sudden changes in behavior might be linked to physical discomfort.
  • Addressing GI issues may improve not just physical health but also mood, learning, and participation.

Supporting Children Day-to-Day

While the study does not prescribe treatments, it highlights the importance of awareness. If a child seems unusually anxious, tired, or shows more repetitive behaviors than usual, it may be worth asking whether stomach issues are part of the picture. Working together, parents, educators, and healthcare providers, can ensure these symptoms are identified and treated.

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MORE HELPFUL RESOURCES

If you’d like to learn more about related topics, check out these articles:

Key Points about Autism and the Gut

  • Children with autism are about twice as likely to have GI symptoms compared to their peers.
  • Constipation, diarrhea, bloating, and stomach pain are the most common symptoms.
  • GI issues are often long-lasting and linked to challenges in sleep, behavior, and sensory processing.

Reference

Restrepo, B., Taylor, S. L., Dominic Ponzini, M., Angkustsiri, K., Solomon, M., Rogers, S. J., … & Wu Nordahl, C. (2025). A longitudinal evaluation of gastrointestinal symptoms in children with autism spectrum disorder. Autism, 13623613251362349.

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