Stats show the number is increasing...it also shows that pediatric IBD is on an alarming rise compared to years ago. There's 2 parts to having IBD, being predisposed to it and an environmental trigger in order to bring the disease "out".
Researchers believe there are alot of environmental triggers and food/diet is not ruled out as one, but they also strongly feel that it's more than likely a combination of environmental factors rather than just one that triggers a patients IBD.
Ah they have soooo much to learn still, I wish they'd figure it out already....but at least in Canada they have the GEM project;
"The GEM Project is a Canada-wide research study that will attempt to determine possible causes for Crohn's Disease by following healthy individuals who are at a higher risk for developing the disease over time....healthy individuals who have a sibling and/or parent with Crohn's Disease will join the effort to help find a cause.
This is the first study of its kind to try and understand the complex genetic, environmental and microbial interactions within our own bodies. If you have Crohn's disease, we encourage you to ask your siblings and/or offspring to participate. If you have a full-sibling or parent that suffers from Crohn's Disease and are between the ages of 6 and 35."
I know this project is specific to crohn's but I wouldn't be surprised if they include UC or will do the same study at some point for UC as well.