The number of Ontario children diagnosed with inflammatory bowel disease shot up 50 per cent in a decade, according to a new study.
The findings, published in today's issue of the medical journal Gut, add new urgency to understanding the root causes of IBD, a sometimes debilitating life-long condition for which Canada already has the highest rates in the world.
Eric Benchimol, a pediatric gastroenterologist at the Hospital for Sick Children in Toronto and the principal investigator, said the study was designed to get a handle on how many children are being diagnosed with Crohn's disease and ulcerative colitis (the two main forms of IBD), but the question everyone wants answered is why the numbers are on the rise.
He said there are three likely reasons for the increase:
A change in immigration patterns that has resulted in an influx of immigrants from South Asian countries such as Sri Lanka, Pakistan and India, who seem prone to IBD when they move to Western countries;
More awareness about the condition - particularly among physicians - resulting in more prompt diagnosis. The diagnostic tools have also improved;
Environmental changes that are somehow causing changes to the immune system, similar to what is occurring with the rise of allergies and asthma.
"It's an immune-system-mediated disease caused by a combination of genetics and environment," Dr. Benchimol said. "We also know that Western lifestyle plays a key role."
The gut is colonized by trillions of bacteria, viruses and fungi living in complex harmony and it is believed that Crohn's and colitis can be triggered when the balance is upset.
There are more than 200,000 Canadians living with inflammatory disease (about 10 per cent of them children), according to a report published last year by the Crohn's and Colitis Foundation of Canada.
That number includes about 112,000 people with Crohn's and 88,500 with ulcerative colitis. The latter is an inflammation of the large bowel, while the former describes an inflammation anywhere in the bowel, from the rectum up to the esophagus.
While Crohn's and ulcerative colitis are principally illnesses diagnosed in early adulthood, the new study notes that they are increasingly being seen in children.
The study in Gut found the prevalence of IBD in those under the age of 18 increased to 56.3 per 100,000 in 2005 from 42.1 per 100,000 children in 1994 and that it is no longer uncommon for children under the age of 10 to be diagnosed.
George Tolomiczenko, executive director of research at the Crohn's and Colitis Foundation of Canada, said the new numbers are troubling because IBD requires life-long treatment.
"We're still looking for a cure so, for now, all we can do is treat the symptoms," he said.
Dr. Tolomiczenko said IBD sufferers tend to be asymptomatic most of the time, but they get hit by flare-ups. Both the suppression of symptoms and treating flare-ups requires medication, ranging from steroids to TNF (tumour necrosis factor) blockers, and they have sometimes serious side effects. Earlier this week, for example, the U.S. Food and Drug Administration warned that TNF blockers, used to treat serious inflammation, can cause cancer in children.
About 70 per cent of IBD sufferers also have surgery to remove fistulas or a part of their bowel.
Aside from the physical symptoms, IBD is a condition that carries a lot of social stigma because of issues surrounding ready access to toilets and difficulty with physical intimacy because of bowel problems.
Symptoms of IBD including a swollen gut, abdominal pain, bloody stools and frequent diarrhea. In children, it is marked by a perpetually sore tummy and prolonged bouts of diarrhea.
The economic cost of IBD exceeds $1.8-billion a year, including $700-million in direct medical costs, according to the foundation report.