The Distinctive Clinical Profiles of Children With Autism Suffering From Different Subtypes of Rome <scp>IV</scp> Functional Gastrointestinal Disorders

Functional gastrointestinal disorders (FGIDs) are prevalent in children with autism and can interact with the neuropsychiatric symptoms bidirectionally. Moreover, FGIDs may affect feeding to jeopardize nutritional intake. Existing research often overlooks the heterogeneity of FGIDs. Understanding the clinical correlates of individual FGID subtypes may clarify the underlying gut-brain interactions to guide management. This study compared the core autistic symptoms, co-occurring psychopathologies, feeding behavior and dietary intake among 737 Chinese children with autism (mean age = 7.76 years; 642 males and 95 females) who either experienced no FGID or experienced one of the three subtypes of ROME-IV FGID. FGIDs were present in 19.8% of participants and MANCOVA revealed distinct clinical profiles across FGID subtypes. Functional abdominal pain disorders (FAPD) were associated with more severe neuropsychiatric symptoms, including restricted and repetitive behavior, anxiety, sensory hyperresponsiveness, externalizing behavior, and feeding patterns of emotional under-eating, slowness in eating, and increased satiety response. Functional defecation disorders (FDD) were characterized by food fussiness, slowness in eating, increased satiety response, and decreased intake of water, protein and fiber. With a small sample size of six, functional nausea and vomiting disorders (FNVD) were associated with emotional overeating. These findings suggest FGID subtypes involve distinct gut-brain interactions. Sensory dysregulation may underlie the link between FAPD and neuropsychiatric symptoms, while food fussiness in FDD may contribute to constipation via reduced fiber and water intake. The management of FGIDs in autism should be tailored to specific subtypes and their clinical correlates.