Having had two rescues that I fostered go thru Bladder Stone Surgery (Cystotomy), I can tell you this is often seen post op and it is not normal!
Most likely, your lil' one is straining because a piece of "gravel" is blocking or irritating him.
After Cystotomy sugery, they often will need to go back in to have their urethra's flushed via a catheter to clear any debris/gravel.
Whatever you do...do NOT wait to get this checked out! Please call your Vet's emergency phone number and follow their advise ASAP!
This is painful, too! Just ask a man who's tried to pass a kidney stone!
