An international team of scientists has shown that stress in early life may increase the risk of gastrointestinal diseases later on. Changes in gut function and the sympathetic nervous system play a key role. The study was published in the journal Gastroenterology (GE).

The researchers focused on the so-called gut–brain axis — a system of constant communication between the nervous system and digestion. Disruptions in this system can lead to irritable bowel syndrome, abdominal pain, constipation, and diarrhea.

In experiments on mice, scientists modeled early-life stress by temporarily separating pups from their mothers. In adulthood, these animals were more likely to exhibit anxiety-like behavior, intestinal pain, and impaired gut motility. The symptoms also differed by sex: females more often developed diarrhea, while males were more prone to constipation.

Additional experiments showed that different symptoms are linked to distinct biological mechanisms. Signals from the sympathetic nervous system affected gut motility but not pain, whereas sex hormones were associated with pain perception. Serotonin was involved in both processes.

The findings in animals were supported by human studies. In one, researchers analyzed data from more than 40,000 children in Denmark. Children of mothers with untreated depression during or after pregnancy were more likely to develop digestive problems, including colic, constipation, nausea, and irritable bowel syndrome.

In another study, based on data from nearly 12,000 children in the United States, a link was also found between adverse childhood experiences — such as abuse, neglect, or parental mental health issues — and an increased risk of gastrointestinal disorders.

The authors emphasize that these findings could help develop more precise treatment approaches. Different symptoms are driven by different biological mechanisms, meaning there is no one-size-fits-all solution.

They also note that when diagnosing such conditions, it is important to consider not only a patient’s current stress levels but also their childhood experiences, as these may play a key role in the development of disease.