Hiding in carrier after vet visit

Hi. Today my cat went to the vet after a urinary tract blockage and they were able to get him cleared. It was obviously very painful for him. After bringing him home he stepped out of the carrier and then went right back in and stayed there. He hasn't moved since and it has been a few ours. Has anyone else had a cat that does this? I've put down food for him to eat that the vet prescribed as well as a bowl of water. My hope is he comes out on his own eventually but he obviously feels safer in the carrier right now.

Has he come out yet?  I'm guessing he has, but cat's like places like caves, as I'm sure you know.  If nothing else, put his carrier in a nice quiet place and he'll venture out when he feels safe.

Hope he feels better soon, poor baby. 

Actually, I slowly pulled the towel that was under him and he came out that way.