Hi,
There is a lot to read about IC on the internet, and i bet you search what could be found, so here is something i can ad.
To what symptoms someone is diagnosed with IC can be different in 1 country or another, or even between 1 doctor or another. Where i live most common symptom is when there are some kind of blisters visible on the bladder wall that causes pain. It usually is caused by bacterias, but an UTI is negative. Patients most often have bladder pain, painful urge and symptoms of overactive bladder. Incontinence is not typical for IC but due to the painful urge patients often can't get to the toilet on time.
I think more than 90% of the patients are female. I am a man diagnosed with BPS, bladder pain syndrome, and chronic bladder infection ( the one thats traceable ). I have the same symptoms: bladder pain, painful urge, overactive bladder and so on …
I haven't heard about different stages of IC. I hope your doctor can give you more advice. Although there is no cure there are some possibilities to ease the pain. Maybe you can find more IC patient forums with more and better information. Good luck!