I would have to say it sure sounds like his anal glands are full. I have one of my boys that has some issues with his ocassionally, and I drain them myself. It isnt hard to do this and it doesnt hurt my boy when I do his myself. Your vet might be able to show you how to do this yourself.
Heres a helpful link:
http://www.marvistavet.com/html/anal_sacs.html