Environmenta/ factors /BD is more prevalent in developed countries and more common in white-collar workers 口 Risk of uc Negative: Breast feeding, appendectomy, smoking Positive. "Western diet left-handedness depression Risk of cd Smoking, second-hand smokeEnvironmental factors IBD is more prevalent in developed countries and more common in white-collar workers Risk of UC Negative: Breast feeding, appendectomy, smoking Positive: “Western diet” , left-handedness, depression Risk of CD Smoking, second-hand smoke