If you or someone in your family has ADHD and lives with chronic constipation, cramping or an unpredictable bowel, a large new analysis suggests the two may be more connected than most patients realize.
Researchers at the University of Warwick pooled data from 23 studies covering more than 1.9 million people and found ADHD was tied to roughly a 50% higher overall rate of gastrointestinal symptoms.
The pattern held across specific conditions.
Odds of constipation were nearly doubled, irritable bowel syndrome (IBS) was 58% more common, and encopresis, the medical term for loss of bowel control, was more than four times as likely in people with ADHD.
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The analysis was published September 10, 2026 in the Journal of Attention Disorders and covered people aged 2 to 65 in the United States, Sweden, Germany and South Korea.
In the United States alone, an estimated 15.5 million adults had an ADHD diagnosis, about 6% of the adult population, according to the most recent CDC national estimate.
If the odds seen in the review apply broadly, a substantial share of those adults may have gut complaints that are not being connected to their neurodevelopmental diagnosis.
Why the gut and the brain may talk to each other
A meta-analysis pools existing studies. It shows association, not cause. But the team points to several plausible drivers that could each play a role.
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Impulsive or irregular eating patterns, common in ADHD, can disrupt normal bowel rhythm.
Stimulant medications used to treat ADHD can slow digestion and contribute to constipation.
And a growing body of work on the gut-brain axis, the two-way signaling network between the gut microbiome and the central nervous system largely relayed through the vagus nerve, suggests that differences in gut bacteria may influence brain function, and vice versa.
What it means if this sounds familiar
For readers, the practical takeaway is a conversation, not a self-diagnosis.
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If bowel symptoms are persistent, worsening, or interfering with daily life, they deserve a medical workup rather than being written off as background noise from a busy nervous system.
The Warwick authors suggest clinicians treating ADHD should routinely ask about gastrointestinal symptoms, and that complex cases may benefit from input from a dietitian or gastroenterologist. That advice cuts both ways.
A gastroenterologist evaluating unexplained IBS or chronic constipation may also want to know whether ADHD is part of the picture, particularly because ADHD in adults is often diagnosed late or missed entirely.
None of this changes standard care for either condition. Anyone taking stimulant medication should not stop or adjust the dose on their own.
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This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.