Autism and Gastrointestinal Comorbidities – Research Updates

Mojdeh Mostafavi, MD, describes gastrointestinal conditions commonly seen in individuals with autism, including gastroesophageal reflux disease (GERD), inflammatory bowel disease (IBD), Eosinophilic GI disease (EGID), avoidant/restrictive food intake disorder (ARFID), disorders of the gut-brain interaction (DGBI), and constipation. She outlines recent research on the prevalence of these conditions in people with autism, emphasizing the complexities of symptom presentation, drivers, and care. The speaker provides a free social story for endoscopies and considers the relationship between pain expression and GI conditions. Mostafavi discusses the difficulties of transitioning from pediatric to adult healthcare in autism. She summarizes the presentation before the Q&A.

Handouts are available HERE

Recommendations for evaluation and treatment of common gastrointestinal problems in children with ASDs – PubMed (article discussed during the talk)
Understanding and Treating Self-Injury Book (book mentioned during the talk)

In this webinar:

1:10 – Introduction, disclosures, language preferences
2:35 – Autism and gastrointestinal conditions
10:20 – Gastroesophageal Reflux Disease (GERD)
14:10 – Inflammatory bowel disease
18:00 – Eosinophilic GI disease (EGID)
22:10 – Avoidant/restrictive food intake disorder (ARFID)
27:15 – Disorders of the gut brain interaction (DGBI)
33:00 – ASD and constipation
37:00 – Resources and tips
46:20 – Conclusion
48:00 – Q&A

Autism and GI conditions

Mostafavi defines autism and lists common co-occurring conditions, including seizures, psychiatric disorders, and gastrointestinal (GI) conditions (2:35). She notes that between ~40% – 70% of children with autism have GI symptoms with a significantly higher lifetime prevalence and that measurement tools don’t capture all GI symptoms (5:30). The most common GI complaints reported by autistic people are constipation, abdominal pain, feeding difficulties, encopresis, and weight loss/failure to thrive (8:40). The speaker underscores the importance of defining these conditions in autism and discusses some of the most common co-occurring GI conditions. 

• The Prevalence of Gastrointestinal Problems in Children Across the United States With Autism Spectrum Disorders From Families With Multiple Affected Members (Wang et al., 2011)
• Gastrointestinal Symptoms in Autism Spectrum Disorder: A Meta-analysis (McElhanon, 2014)
• Gastrointestinal Symptoms in Children with an Autism Spectrum Disorder and Language Regression (Valicenti-McDermott et al., 2008)
• Characterization of Initial Gastrointestinal Evaluation of Children with Autism Spectrum Disorder: A Descriptive Study (Mostafavi et al., 2024)

Gastroesophageal Reflux Disease (GERD)

Gastroesophageal Reflux Disease (GERD) occurs when stomach acid refluxes into the esophagus. This is one of the better-understood GI conditions in autism. Mostafavi outlines a recent study that found that people with autism have a higher risk of developing erosive esophagitis and esophageal ulcers compared to non-autistic groups (10:20). She remarks that acid-blocking medications can mitigate some risk and describes the BRAVO wireless and nasal probe tests for GERD (10:20). 

• Evaluation of Gastroesophageal Reflux Disease in Children on the Autism Spectrum: A Study Evaluating the Tolerance and Utility of the BRAVO Wireless pH Monitoring (Rodriguez et al., 2022)

Inflammatory bowel disease

Inflammatory bowel disease (IBD) is broadly characterized by Crohn’s disease and ulcerative colitis, which are caused by inflammation of the GI tract. A recent systematic review and meta-analysis (6 studies, 11 million participants) found an association between autism and the later development of IBD. Mostafavi notes that children with autism often have more potent treatments (second-tier biologics) for GI conditions compared to non-autistic children with GI issues, underscoring their severity in autism (14:10). 

• Association of Autism Spectrum Disorders and Inflammatory Bowel Disease (Lee et al., 2018)

Eosinophilic GI disease (EGID)

Eosinophilic GI disease (EGID) looks at the entire GI tract and is associated with an imbalance in the immune system potentially related to food sensitivities. Over time, complications can include fibrosis and eosinophilic esophagitis (EOE). The speaker outlines a recent systematic review and meta-analysis (6 studies, +700,000 participants), which revealed an association between autism and EGID, where the prevalence of autism in the EGID population is 21.59% (18:00). 

Avoidant/restrictive food intake disorder (ARFID) 

Avoidant/restrictive food intake disorder (ARFID) is related to at least one of the following:

• Fear of consequences (symptoms that the food triggers)
• Sensory aversion
• Lack of interest/awareness of appetite cues 

Unlike other eating disorders, ARFID is not related to body appearance. Mostafavi notes inadequate caloric intake and deficiencies in micronutrients and vitamins as concerns associated with ARFID. Recent research shows a significant relationship between autism and ARFID, and sensory issues are the most commonly described driver (22:10). The presenter suggests trying treatments like oral desensitization and pairing foods and asserts that applying what works in other intervention spheres to ARFID may be possible (25:20). 

• The Co-Occurrence of Autism and Avoidant/Restrictive Food Intake Disorder (ARFID): A Prevalence-Based Meta-Analysis (Sader et al., 2024)
• Avoidant/restrictive food intake disorder and severe food selectivity in children and young people with autism: A scoping review (Bourne et al., 2021)

Disorders of the gut brain interaction (DGBI)

The gut-brain access involves both nervous systems; many neurotransmitters are produced in our guts. Mostagavi asserts that just because labs come back negative does not mean that GI symptoms are not real because there is no specific test for DGBI (27:15). A retrospective study found that nearly one-third of participants seen through an autism-specific clinic experienced functional GI conditions. The speaker underscores how difficult pain localization can be for people with autism due to complications with interoception (31:00). 

• Functional Gastrointestinal Disease in Autism Spectrum Disorder: A Retrospective Descriptive Study in a Clinical Sample (Penzol et al., 2019)
• Characterization of Initial Gastrointestinal Evaluation of Children with Autism Spectrum Disorder: A Descriptive Study (Mostafavi et al., 2024)

Autism and constipation

Constipation is one of the most reported GI symptoms associated with autism. However, chronic constipation does not seem to be associated with a higher rate of abnormal colonic motility in autism. Mostafavi outlines research showing that children with autism are more likely to visit the ER and be admitted to the hospital for constipation-related issues compared to children with other or no chronic conditions. This significantly increases healthcare costs and utilization, increasing the chances of poor quality or lack of treatment (33:00). 

• Evaluation of Chronic Constipation in Children With Autism Spectrum Disorder (Coe et al., 2023)

Resources and tips

The presenter notes a 2010 article published in Pediatrics as a good reference for GI issues in autism. The article talks about constipation, guidelines for evaluation in patients with high-risk, mitochondrial conditions, and medication (37:00). Mostafavi suggests using a joint provider who can obtain information on health history, blood and stool work, imaging studies, etc., to compile a complete picture of drivers and symptoms (38:15). Endoscopies can be particularly helpful in assessing GI disturbances in autism and Mostafavi provides a free endoscopy social story available in English, Spanish, Brazilian Portuguese, Arabic, and Haitian Creole (40:00). 

Access Google Drive with social story documents – https://bit.ly/endoscopysocialstory

The speaker highlights that many behavior issues in autism are associated with pain, like irritability, oppositional behavior, meltdowns, and more. She notes the Understanding and Treating Challenging Behaviors in Autism book and how it describes causes of aggression and self-injurious behavior (SIB) in autism as having both physiological and social/behavioral causes. She lists pain behaviors that are often misinterpreted, highlighting that people can demonstrate one or many forms of behavior across different contexts (41:55). Mostafavi touches on the transition from pediatric to adult care and how difficult it can be for autistic people to acquire the necessary care and support (44:00). 

Summary

The speaker summarizes the presentation, highlighting that the majority of people with autism have associated GI-related symptoms or conditions, the most common of which are DCBI, GERD, IBD, EGID, and ARFID. She emphasizes the importance of comprehensive evaluation with guidance from a gastroenterologist where necessary. Mostafavi reminds viewers that children with autism become autistic adults with similar care needs (46:20). She notes the ongoing complexities of discourse around the association between GI issues and autism before the Q&A (48:00). 

Originally published on March 4, 2025.