So I started out keeping my puppy inside. But he started having diarrhea so I left him out for a few nights. Now he refuses to eat. He still drinks water but will not eat any food... Please suggestions/recommendations desperately needed.
The diarrhea and refusing to eat, is your signal to get him to a Vet for an exam. There is something going on, and you need your Vet to do a medical workup to determine what, and start appropriate treatment.