Thanks guys! That makes me feel better. He talks to himself and everything when he is in his quiet room, so I guess that he is not sick. He doesn't act sick either. It just makes me nervouse that he is in there alone (wihout a person in sight) most of the day and all night. I was about ready to give up on him. The constant screaming was getting to all of us. We tried time out in the bathtub, but that didn't work. He only learned to say "No screaming-tub". Because I would tell him "No screaming or you will go sit in the tub". And he learned to sound like the timer that I set, so I didn't forget that he was in the tub.
I will trust your opinion that he will tire of this and want to come back out with the family. Again many thanks.
Ginger