Phenazopyridine
"I've suffered from Interstitial Cystitis since I was about 13 (now 29) I wasn't diagnosed until about 3 years ago up till then doctors always tried saying it was UTIs but every urine​ test always came back negative. Since I was 13 I've always had azo pills on me. They are my savior ..  they taste horrible but work with in 10 to 15 minutes after taking. Only thing is now I'm worrying about taking them so much due to just recently after taking them I had blood in my urine and severe nausea and chills"