I am a first time mom, going through the same stuff! My girl had her first tooth come in right before 9 months, although everyone has been saying she was teething since 3 months? I am a big reader and all of the problems we associate with teething (diarrhea, constipation, fever, etc) aren't related according to doctors.
I have been using Humphrey's Teething tablets, you just stick one under their tongue and they can roll it around like a piece of candy before it dissolves. The extreme times when the tablets don't work I use store brand tylenol.
I also agree with using the washcloth in the freezer, but we re-wet the ends b/c she likes to suck the water out of the washcloth.
Lately poop has been on the runny side, but when she was a newbie she was always constipated, we put 1tsp prune juice (adult, not the kid version) in about 2 bottles a day. If you try the prune juice start w/ one tsp per bottle till you get a bm, b/c if you give too much you'll have a different set o problems! LOL Good Luck!