The main pesticide they use now is called neonicitinoids. Basically it shuts down their immune system and they get symptoms like autoimmune disease and die.
I remember hearing that on the special - that also concerned me as I personally smoke. (I believe that is a Nicotine based pesticide correct me if I'm wrong) I felt that there was a real practical reason for me smoking. What I mean by that is, as my disease worsened (then undiagnosed despite full physical and trip to a GI) , I felt the need suddenly to chain smoke all the time.
Plus the whole 'word on the street' thing that smoking helps UC but not Crohn's I guess. Please note; I am not condoning smoking as a medical treatment. It always makes me curious how in the literature you always come across that UC is "a disease of non-smokers." I certainly was smoking my behind off before DX. Seems almost *too* convenient to come across that in the scant, typically un-unified literature on UC, but I digress into yet another RJ Reynolds, Phillip Morris, conspiracy theory. Forgive me, my intentions are good.