i like rainbow's idea. get one 'spokesperson' for your group go talk to one of the other Ts and then let that T address it with the offending T in private. i think an anonymous note would be really hurtful.

having been told i likely had bowel cancer a few years ago, and feeling devastated enough about the situation, it really would have hurt even more for my friends and/or colleagues to send anonymous notes my way. a concerned "i've noticed you have a problem with x,y,z and was wondering if everything is ok" is direct and open and honest and something i appreciated. my problems weren't related to flatulence at all, but still weren't "polite conversation" topics, and having an anonymous note would have been a nice big flag for shame to set in.