There's not much worse than having a stomach bug — unless it's watching your child suffer through the vomiting and diarrhea that go along with it.

Most young children will get at least two intestinal infections each year and now, Alberta researchers are launching a new study to figure out exactly why. Doctors say there are more than 30,000 children hospitalized for intestinal infections in the province each year, but they don't always know which specific virus or bacteria is causing the illness.

"Understanding what actually causes the symptoms of vomiting and diarrhea in kids is important to caregivers," said Dr. Stephen Freedman, an associate professor of pediatric emergency medicine and gastroenterology at the University of Calgary and lead researcher of the study. "As we gain knowledge of the specific pathogens, we can in the future tailor therapies to those pathogens to provide optimal care to children with vomiting and diarrhea."

So far, Freedman says most research has focused on children whose parents seek hospital care for their illness.

About half of the subjects in his study will be those seeking medical attention, but he says the study also wants to look at children who are not brought to a doctor.

Freedman says that is important because roughly 90 per cent of children with diarrhea and vomiting are not brought to a doctor.

Researchers are hoping to enrol 4,500 children in the study. Parents can call HealthLink at 1-866-408-5465 (LINK) for advice on how to participate.