Hi Sandy
have you found the tourette forum here?
http://neurotalk.psychcentral.com/forum25.html
So many things can trigger tics, from diet & allergies to genetics, thru illness/infection and vaccines and more.
many parents are also finding docs are often quick to give a TS diagnosis, without first investigating the possibility of these other triggers, mainly because a lot of conventional doctors just either dont know of, or too easily discount the volumes of anecdotal evidence out there if they would just look. Research is beginning to point to it too.
there is a very good site for general information on Tourette at
http://www.tourettesyndrome.net