Seven years ago I had a normal bout of cystitis due to cold weather and a draught - this always brings it on for me if I'm not well wrapped up. Then a week later I got a bladder full of different sensations: pressure, irritation- like it was all shrivelled up, the need to urinate thimblefuls, like I had a cannonball in there, a sensation of grittiness. This lasted for a year. I had an internal exam of the bladder at the time which looked fine.