Research highlights increased digestive problems among people with ADHD, prompting calls for broader clinical assessments

A comprehensive review of over 1.9 million individuals reveals that those with ADHD are significantly more prone to gastrointestinal issues, suggesting the need for holistic health approaches in treatment.

A large review of research has found that people with attention deficit hyperactivity disorder are substantially more likely to experience digestive problems than those without the condition, adding to evidence that ADHD may affect far more than attention and behaviour.

Writing about the findings, Science Alert said the analysis drew on data from more than 1.9 million people across 23 studies. The review, published in the Journal of Attention Disorders, found that ADHD was associated with a 48% higher likelihood of gastrointestinal symptoms overall.

The strongest links were seen in several common gut complaints. According to the study, people with ADHD had 52% higher odds of dyspepsia, or indigestion, and a 58% higher chance of irritable bowel syndrome. The risk of abdominal pain was 88% higher, while constipation was up by 97% and diarrhoea by 118%. The sharpest rise was seen in encopresis, a loss of bowel control, which was more than four times as common in the ADHD group.

Researchers said the pattern may reflect several overlapping factors. They pointed to the stress reactivity often seen in ADHD, which could affect the gut directly, as well as impulsive eating habits and irregular mealtimes. Diet may also play a part, with some people relying more heavily on sugary drinks and eating too little fibre. Medication and sleep problems were also identified as possible contributors, with disrupted sleep thought to affect immune responses and increase vulnerability in the digestive system.

The findings do not prove that ADHD causes gut disease, but they do strengthen the case for clinicians to ask about digestive symptoms when treating patients with the disorder. The study adds to a growing view that ADHD should be understood as a condition with wider physical effects, not only a neurodevelopmental one.