[Blarg]

I'm sure it generally doesn't.

I'd see a professional about this. It's not remotely normal. I would be surprised if it was physical, considering he has past problems with his pooping that are the exact opposite of what he's doing now. Not that I'm a doctor, just saying ....

I also find it hard to believe a well-adjusted kid wouldn't be screaming to go to the doctor for a problem like this, so it sounds like he needs some sort of counseling or something. I think leaving a kid in a state like this for four months is probably not very healthy for him at all. He needs some professional intervention. Your folks might, too, to learn how to handle this and see if there's anything they can do to make things better.