Canada has the highest rate of inflammatory bowel diseases (IBD) in the world. The typical age of onset is some time around 20. But new data shows a growing number of young children -- even babies -- are developing the painful and incurable disorders. It’s an alarming trend that has researchers baffled.

“You speak to some of the older doctors who have been practicing for 20 or 30 years, they almost never saw children under five (diagnosed),” says Dr. Eric Benchimol, a pediatric gastroenterologist at the Children's Hospital of Eastern Ontario, in Ottawa.

“Now it’s almost a regular occurrence."

IBD includes Crohn’s disease and ulcerative colitis, conditions that cause inflammation in the digestive tract, leading to chronic diarrhea, blood in the stool, abdominal pains and weight loss.

A new study, which analyzed data from five Canadian provinces, has found that cases among children five and younger have jumped 7.2 per cent per year between 1999 and 2010.

Researchers suspect a combination of factors could be to blame, including genetics, the environment and lower levels of Vitamin D.

Another possible factor is the depletion of so-called good bacteria in the digestive tract, as a result of changing diets.

“By not exposing immune systems to certain types of bacteria,” Dr. Benchimol explains, “the gut is not being able to be populated with a normal healthy composition of good and bad bacteria.”

While the exact cause behind the spike in IBD among children remains a mystery, the impacts are devastatingly clear.

Kassandra Behne’s daughter Myla was diagnosed at age four. Pain, diarrhea and severe fatigue have at times kept her out of school.

“It can be emotionally and physically exhausting to see your child in pain and tired,” Behne said.

Powerful immune drugs designed for adults are currently are the only treatment option for children like Myla.

After a lot of trial and error, she’s found a drug that has allowed her to return to school, but managing her condition will be a lifelong struggle.

It’s unclear what the long-term effects of the medications will be, according to Dr. Benchimol.

The disturbing and unexplained rise in pediatric IBD is surfacing outside of Canada as well.

“In France, we are catching up with what is (happening in) Canada, and yes we are worried by the very high numbers,” said Dr. Frank Ruemmele, a gastroenterologist from Hôpital Necker Enfants Malades in Paris. “We would like to be able to prevent this increase, but up to now there is no proven strategy to prevent this.”

Nearly a quarter of a million Canadians are living with IBD. More than 10,000 new cases are diagnosed every year. That breaks down to 28 to 30 people every day, according to a 2012 impact report from Crohn’s and Colitis Canada.

With a report from CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip