ADHD Is Linked To More Gut Issues, Including Constipation

Gut issues like constipation are pretty common – about one in seven adults face backed-up bowels at any given point in time.

But a new study published in the Journal of Attention Disorders has suggested that those numbers may be even higher for those with attention deficit/hyperactivity disorder (ADHD).

In fact, the systematic review and meta-analysis found greater associations between ADHD and a range of gut issues, including irritable bowel syndrome (IBS) and diarrhoea.

This research looked at 23 studies involving 1.9 million participants overall.

According to the paper, compared to people without ADHD, those with it appear to be:

• almost twice as likely to experience constipation,
• roughly 1.6 times more likely to have IBS,
• over four times more likely to experience loss of bowel control (encopresis).

Overall, ADHD was linked to a near 50% increase in the likelihood of any gastrointestinal symptoms.

One of the study’s lead authors, Sarah Blake, who’s a medical student at Warwick Medical School, said: “Almost every gut symptom we looked at: constipation, IBS, even indigestion, appeared to be associated with ADHD. These symptoms can have a real impact on daily life, but they could easily be overlooked if the focus is on ADHD itself.”

Meanwhile, the paper itself reads: “An increase of gastrointestinal (GI) symptoms is well documented in autism spectrum disorder, but the extent of GI involvement in ADHD has not yet been systematically evaluated.”

This paper only found a link between ADHD and a higher rate of gut issues – it didn’t even show that ADHD definitely caused the health problem, never mind why.

“We can’t yet say ADHD causes these gut problems, or exactly what is driving the link, but the pattern is striking enough to warrant attention,” said Dr Saran Shantikumar, an Associate Clinical Professor at Warwick Medical School.

Still, researchers have theories.

Possible explanations include the side-effects of ADHD medications, behaviours like impulsive and/or irregular eating, and differences in gut bacteria, which might impact the vagus nerve.

No matter the exact mechanism, Dr Shantikumar advised: “Clinicians caring for people with ADHD may want to consider asking about gastrointestinal symptoms, particularly if they may be affecting quality of life.”