C.,
My 19 MO daughter had her four front teeth until about 16-17 mos and then got two molars (one top one bottom) and then got another front top tooth, then another molar on top and then another bottom front tooth, so now she has three each on top and bottom on the front and her top molars and one bottom one. She will get diarrhea about 2-3 days prior to cutting a tooth - anyone will tell you it's not related, but I'm convinced it is and their diet has nothing to do with it. Heck, I'm thankful she got her molars before the others because a) they're the most painful and I'm glad she's getting it over with and b) she can really chew her food now!
Enjoy this stage, and give lots of mommy love - it won't last long.
Best, L.