Re: Diareaha what should I do???
Often (even usually) the cause of unexplained diarrhea in kittens and young cats are giardia and/or coccidia. They are both very difficult to find on a fecal so it can take several tries to confirm. When my vet suspects them he'll just go ahead and treat for one (the more common one, but I don't remember which that is). If that doesn't do it, he treats for the other. Nine times out of ten, that does the trick.
Unless you've recently changed the food and did it too fast, I think it's unlikely that that's the culprit. Especially since they both have diarrhea. If, however, you've completely ruled out parasites and they still have it, just try another good food like Innova or Prairie. But make the switch very slowly. Switching a diet too fast, especially in kittens, can cause upset tummies.