No don't feel bad or anything, that was my initial thought too; maybe his body was just... slower at digestion or something.

Well CRAP this is something that I JUST thought of. We had a lot of company staying over, we had five friends come in town and stay with us for two nights and Charlie is very skittish around people, even me and HJ sometimes. Maybe he was nervous or stressed out, and that's why it happened??? That would make COMPLETE sense!