Someone call it "princess chunk". He is big and got "idiopathic Feline Urinary Syndrome" half years ago. After staying in an animal clinic for 2 days, he could urinate again. However, he has to take medicated cat food for the rest of his life.
I kept asked the Vet about the etiology and the answer was "idiopathic". What that means is "Who knows?". It just like some Medical Docs respond to your curiosity: "It's viral" when they want to get rid of you after they have done with you.