7 week old kittens - eating advice x?

all cat vary on taste what 1 like the other dont unlike dogs they will eat anything put in front of them. not cat try a different kind of food cat need a little bit of wet food for their system anyway,i have two cats and both eat different food, they get 1/2 can of wet food mornin and even, but there a bowl of dry food there all the time for them to eat all day. and as for the diarrhea take them to the vet it could be worms