A comprehensive review of over 1.9 million individuals reveals that people with ADHD are considerably more prone to gastrointestinal issues, prompting experts to recommend wider health checks beyond behavioural symptoms.
A large review has found that people with attention-deficit/hyperactivity disorder are more likely to experience digestive problems, adding to evidence that clinicians may need to look beyond behavioural symptoms when treating the condition. The analysis, published in the Journal of Attention Disorders, pooled findings from 23 studies involving more than 1.9 million people in the United States, Sweden, Germany and South Korea, with participants aged two to 65. It is the first systematic review to focus specifically on gastrointestinal symptoms in ADHD.
Researchers at the University of Warwick found that people with ADHD were about 50% more likely to report gastrointestinal symptoms than those without the disorder. The clearest links were with constipation, irritable bowel syndrome and encopresis, a loss of bowel control. In the review, constipation was nearly twice as likely in people with ADHD, IBS was 58% more common, and encopresis was more than four times as likely.
The reasons for the association are not yet clear. The researchers said impulsive eating patterns, irregular meals and other dietary habits linked to ADHD could play a part, while medicines used to treat the condition may also contribute to digestive side effects such as constipation. Other work on the gut-brain axis, including reviews indexed in PubMed, has suggested that changes in gut bacteria may influence brain function and behaviour, although those studies have also stressed that the biology remains uncertain.
The authors said doctors should consider asking patients with ADHD about bowel and stomach symptoms, particularly when those problems affect daily life. They also suggested that some patients may benefit from advice from a qualified dietitian. But they cautioned that the findings show an association rather than proof that ADHD causes gastrointestinal problems, and the review cannot say whether symptoms are driven mainly by behaviour, medication, biology or a mix of factors. Further research, they said, is needed to understand whether improving digestive health could also improve overall wellbeing.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
