Midnight gets a ultrasound next week to see if he need bladder surgery!!!

Midnight had been on the s/d 2 months now and my sister says he still peeing all over th eplace even on her clothes.
Do you think I should go with her to the vet when she takes Midnight?
She said the vet said if he still has crystals he will need surgery which I do not understand. He is not blocked.
Midnight sees the same vet Coco goes to for her bladder problems.
They have not been able to get urine from Midnight to see if he has a infection.
He has had 2 ultrasouns that show crystals.

If the kitty cat has large crystal formations which are in the bladder and not disolving, he could need surgery to remove them. Calcium oxalate crystals are sharp and irritating, and also have tons of nooks and cranies that harbor bacteria.

However--I would NOT send a cat to surgery to remove the crystals without having a positive diagnosis of what they ARE. Were I in your sister's shoes, I would take the cat in for the ultrasound and demand a UA before deciding surgery or no. If the kitty doesn't have urine, I would leave him there for fluids until they would be able to obtain some.

Going into surgery without knowing what's really going on is something I prefer to avoid at all costs.

I have left Coco there for fluids so I know the vet will do it.
He will have another ultrasound also.