Should I keep an eye out to make sure he does not become dehydrated? Should I be feeding him just his kibble or giving him something else to help him out?? And do you think the bleeding is from "explosive diarrhea" or if its from a bigger problem??

Sorry so many questions but I'm just worried as I'm about to leave again. I'm going to put him in the bathroom with the linoleum (easier to clean up if he does have an accident). I feel bad as my bathroom isn't too big, but I can't leave him outside on a tieout while I'm gone, I WON'T leave him on a tie-out.