Maybe I am the exception as a mother of a boy who regressed after about 12 months of being accident-free. Do not put this kid back in diapers or pull-ups. If you aren't prepared to clean him up constantly then I absolutely understand, but give notice. My son went through at least 6 pairs of underwear A DAY in jk and sk. He wasn't bothered what people thought of him so there wasn't an incentive in the world that would make him go unless he wanted to.

We like to find out the cause of something or label a behaviour because then we have a greater chance of being able to "fix it" and solve the problem. This kid doesn't need to go to the doctors if there are no other things presenting with the regression. If the child was anxious, emotional beyond their norm or other things, then I'd say go to the doctors, but otherwise, you need to just be patient and in all likelihood terminate because it isn't manageable in group care.

My son wasn't a badly behaved child EVER. He is just a unique being who was lost in his head. No need to punish, just constantly reinforce what he should do and what he shouldn't do and try to condition him at the very least and in time he will come through it. This type of child is not always intentionally lazy it just isn't important to him. If he isn't upset by consequences now, then why do you think it's suddenly going to change now. Making this a huge negative issue multiple times a day would work within a few days for some children, but this type just doesn't care. I managed to deal with it once I let go of my expectations and realised that this was how it was and I had to just keep going until he snapped out of it. If this is stressing you out terminate. I can assure you that he cares a lot less about it than you do and while you are stressed out and frustrated, that will only make it worse.