TUESDAY, Sept. 15, 2026 (HealthDay News) — ADHD is linked to a nearly 50% increase in GI problems, a new evidence review says.

The association was even stronger for specific GI problems, including an almost doubled risk of constipation, a 58% increase in irritable bowel syndrome and more than four times higher odds of losing bowel control, researchers reported Sept. 10 in the Journal of Attention Disorders.

"Almost every gut symptom we looked at: constipation, IBS, even indigestion, appeared to be associated with ADHD,” said lead researcher Sarah Blake, a medical student at the University of Warwick Medical School in the U.K.

"These symptoms can have a real impact on daily life, but they could easily be overlooked if the focus is on ADHD itself," she added in a news release.

There are several potential explanations for these links, including ADHD-related eating patterns, side effects from medication and even ties between ADHD and gut bacteria, researchers said.

For the new study, researchers pooled data from 23 previous studies of ADHD and GI symptoms. As many as 1.9 million people participated in the studies.

Overall, a diagnosis of ADHD was associated with a 48% increase in GI symptoms, researchers found.

“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,” senior researcher Saran Shantikumar, an associate clinical professor at Warwick Medical School, said in a news release.

Possible reasons behind this link include, according to researchers, include:

• ADHD-related traits like impulsivity and irregular eating patterns, which might affect digestion

• ADHD medications, which are known to cause gut problems like constipation

• ADHD-linked differences in gut bacteria, which might interfere with communication between the gut and the brain

Doctors treating people with ADHD should be alert to gut symptoms and might consider looping in a dietitian or GI doctor if patients have complex or severe symptoms, researchers said.

“Clinicians caring for people with ADHD may want to consider asking about gastrointestinal symptoms, particularly if they may be affecting quality of life,” Shantikumar said.

More information

John Hopkins Medicine has more on gut health.

SOURCE: University of Warwick, news release, Sept. 10, 2026