My kitty help please.........?

My kitty has been sleeping the whole day. He woke up at 7am ate and went back to sleep. Woke up again at 12 pm, crawled ate went pee pee and back to sleep then he woke up around 2 pm ate had a bowel movement and went back to sleep. I just woke him up and he couldn't even say meow, he did eat but right now he just went back to sleep. He's purring but he's just not the same kitty the one that used to cry and crawl on the bed. He went to the vet and he said he was healthy. I will take him again tomorrow.