Autism Spectrum Disorder and Associated Gastrointestinal Issues

Abstract

Introduction and Definition: Autism spectrum disorder (ASD) is a “collection of conditions regarding brain development”; it presents with a diverse spectrum of characteristics and severity. It is well documented that people with ASD face gastrointestinal (GI) issues at a much higher frequency than the neurotypical population. This can drastically reduce their physical quality of life as well as hinder many social situations. The etiology is complex with multiple factors centred around the gut-brain axis.

Presentation & Impact: The GI issues faced by those with ASD commonly include nausea, chronic constipation, diarrhoea, gastroesophageal reflux disease (GERD), chronic flatulence, gut inflammation, ulcers, and more. These problems carry extra baggage as they often lead to further distressing reactions. For example, posturing, self-harm, and outbursts are regularly reported – especially as those with ASD struggle to articulate the pain/issue. In the long term, GI issues affect mood, learning, as well as sleep (which can exacerbate the previous behaviours, particularly aggression). From a social perspective, this can impede on the social life of those with ASD.

Etiology: The gut-brain axis – the two-way influences between the gut microbiome and the brain – seems to be at the core of most GI issues. People with ASD often have gut dysbiosis: an imbalance in their gut bacteria. While there is an excess of pathogenic bacteria, there is a lack of beneficial ones as well as a decrease in bacterial diversity. Other issues commonly associated with ASD contribute to this: digestive enzyme deficiencies (such as absence of lactase), selective eating (for example, with eating sensory issues), medication, and more. The issue of selective eating itself causes many of the GI symptoms; an unbalanced diet can cause diarrhoea, constipation, reflux, and intestinal motility issues.

Treatment & Management: Treatments are usually behavioural. For children, clinicians work with parents to incorporate more balanced meals. Therapy is also used to overcome sensory issues and mealtime-related anxiety. However, specific medications such as laxatives or probiotics can be administered to relieve persistent symptoms.