That is interesting. I grew up in Tucson, but live in LA, and I often wonder if I stayed in Tucson if my symptoms would be as severe. Also, I lived in Lake Tahoe for a year and felt much better during that time. A pharmacist once told me about a study they did in Israel that really indicates that it's environmental. When Israel was first being resettled and was mainly agricultural and folks lived on Kibbutzes, there were no reported cases of Crohn's/Colitis type symptoms at all. Jump to the last 20-30 years when Israel has become very Westernized and not as agricultural, and there are many cases. Much like Inida, the hypothesis this pharmacist gave was that when we all lived in more agriculturally based socieites and everything was not germ free, our bodies were constantly fighting foreign invaders. Now that we live in such an "antibacterial" santisized society our immune systems have begun attacking themselves. So, you put a genetic predisposition for the disease together with an overly-sanitized world and you get lots of folks with Crohn's and UC. That's obviously a very synthisized version of his theory, but it made a lot of sense to me.