I believe processed foods are the biggest culprit of the illness. What frustrates me most is that its a viscous cycle because these foods hurt is but as IBD patients we often rely on the unhealthier food to survive. Sure I can buy organic (and I do) but I can't opt for whole wheat or whole grain, instead I need denatured white flour products. I can't eat nutrient dense cancer fighting foods like most fruits and vegetables and I can't benefit from the healthy fats in nuts and seeds unless I do small amounts of nut butter. It leaves a lot of us with junk foods. As for pollutants in the air, we can't escape that either. As long as humans don't wake up to the damage we are doing to ourselves, sadly these illnesses will continue to rise and new ones will form at alarming rates.