Kids starting daycare may be at increased risk of stomach bugs during the first year but then have few infections later on, according to researchers in The Netherlands.
The results suggest that daycare may ultimately protect children from stomach infections over time.
So-called acute gastroenteritis is an important cause of illness and doctor visits in developed countries, particularly among preschoolers in the winter, said senior author Marieke de Hoog of the University Medical Center Utrecht.
While daycare has been linked with an increased risk of stomach bugs, less was known about whether the risk decreases later in childhood, her team writes in Pediatrics.
For the new study, the authors tracked 1,626 Dutch children for the first six years of life, including 1,344 who attended daycare before their first birthday.
Over those six years, there were about 12 stomach infections each year for every 100 children in daycare, compared to about 13 infections among those not attending daycare.
While rates of infection were similar across the entire six years, the children in daycare were about 13 percent more likely to be diagnosed with acute gastroenteritis during the first year, compared to kids who weren't in daycare.
Children in daycare had a lower risk of infections from years three to six, compared to kids not in daycare, the researchers found.
"It is even possible that the protective effect persist beyond six years of age, however more research is needed to support that," wrote de Hoog in an email to Reuters Health.
Dr. David Dunkin, pediatric gastroenterologist at The Mount Sinai Hospital in New York City, said the increased risk of stomach infections in the first year of daycare is likely a result of kids being exposed for the first time to the stomach infection-causing germs.
"If (parents) can hang in there for the first year of them being sick, then the time after that is going to be pretty calm with less infections," said Dunkin, who was not involved with the new research.
The new study can't say why children in daycare seem to have a lower risk of infection as they get older, but de Hoog said the body may learn to protect itself.
Dunkin said the best advice for parents with kids suffering with a stomach infection is to make sure they're getting plenty of liquids.
"A lot of these kids aren't going to want to eat, because they're not feeling well, but we suggest small sips frequently," he said.