Mine get diarrhea now and then. I just change up their diet (which usually consists more of treats than good for them food...). It doesn't seem to hurt, just makes for a messy cleanup for me.
I'm new at being a chicken Mom so hopefully someone more in the know talks to you, but it hasn't seemed to hurt mine... obviously something in their diet, though. What are you feeding them?
It might mean that they are just warm. Chickens loose body heat by drinking extra water and passing wet stools to get rid of the excess body heat. Could be the same for your chicks.