The only time Ive ever heard of any animal rubbing their bum on the floor (like sitting and scooting) is when anal glands are blocked up. Id get the kitty to the vet to get them unblocked. My BFs dad has a doxie who has problems with that and thats they que to get her to the vet to get unblocked......
Most likely it is anal glands (may not be blocked, might just be full) and possible worms. Often just the scooting can relieve the glands but if it keeps up at all, bring him to a vet where they might "express" them. This is not something you can do on your own unless you are trained to do it, and even then, it is a very messy job.
I agree....
it is essential that your vet check this out asap to determine the cause of the scooting.
Scent sacs can become infected if they become plugged.
That is a whole other ordeal.
It's vet time.