My cat has not been eating. Is he constipated?

by Irene
(Colo.)

My cat has been sleeping for 3-4 days and not eating. He's an outside/inside cat. Is he constipated?

We've had this cat about 5 years (Stinky). He came to us from the neighbors. He is about 6 years old. The last few days (3-4) he has been sleeping a lot. He is not eating, or very little, if any. He played this morning. But with the 4th of July and construction going on in our neighborhood he has been very nervous. Can he be constipated?