ADHD Linked to Markedly Higher Rates of Gastrointestinal Problems

Overview

• The University of Warwick systematic review published on Sept. 11, 2026, combined 23 studies with more than 1.9 million participants to examine gut symptoms in people with ADHD.
• People with ADHD had about a 50% higher chance of any gastrointestinal symptom, nearly double the odds of constipation, a 58% higher odds of IBS, and more than four times the odds of encopresis.
• The analysis covers ages 2 to 65 across multiple countries but cannot prove cause because included studies varied in design and could not separate medication effects or behavioral confounders.
• Study authors say clinicians should ask patients with ADHD about digestive symptoms and consider dietitian or gastroenterologist referral for complex cases.
• Researchers call for targeted studies to test causal pathways—such as medication side effects, eating patterns, and microbiome differences—because population prevalence of ADHD means gut comorbidity could affect many people's quality of life.