It sounds like he is much better! I would probably go ahead and make the switch. Another thing I did when we had potty problems early on was to switch them to bottled water. I bought one gallon, and by the time they had finished it, I put them back on tap and all was well. I think Pepto would be alright, a tiny amount, but I think it is for diarrhea so might not be necessary. I would get a tube of Nutrical (or like) it will last a year or so.
I might have said last night that I keep those little bags of moist Pedigree around for when my pups wont eat. I also try anything to make them eat. I guess it is the sign they are getting better. Also, wouldn't worry about number of poops as long as the consistency is good
