A new study published in the American Journal of Gastroenterology shows that Canada has the highest incidences of ulcerative colitis and Crohn's disease, otherwise known collectively as Inflammatory Bowel Disease (IBD), in the world. The country was noted to have the highest incidence of per capita cases in the world with about one in 350 Canadians suffering from ulcerative colitis or Crohn's disease.
IBD is a wearing away of the lining of the intestinal tract until it becomes red and raw and begins to bleeds, like a skinned knee. The difference between ulcerative colitis and Crohn's disease is where they occur: ulcerative colitis occurs only in the large intestine, and Crohn's disease, which is more common, occurs in both the large and small intestines.
"The key issue about IBD is that it affects people in the prime of their lives--it's usually first diagnosed between the ages of 15 and 25--and it can be very debilitating," said Dr. Richard Fedorak, director of the University of Alberta Division of Gastroenterology and a co-author of the study.
Fedorak and his colleagues are studying IBD incidence rates in Canada to gain insight into the causes of the disease and determine why, as other studies have shown, it occurs more often in northern regions of the world.
"We know that people need a certain genetic mutation to be vulnerable to the disease," said Fedorak. "However, we believe there is an environmental element to it, as well, because not all people with the genetic mutation develop the disease."
Fedorak said the disease does not exist in some parts of the world, such as China and Africa. The explanation for this, he added, may be that children in developed countries are not exposed to as many intestinal bacteria as are children in the developing world, and, therefore, some children in the developed world may not develop immune systems that are able to prevent IBD in adulthood.
"There are theories, but at this point we're not really sure what causes IBD," Fedorak said. "But if we can find the causes and understand the disease a little better, then of course this might lead us to develop treatments or even be able to prevent it, and that's what we're working toward."