interstitial cystitis
"Since entering menopause, I find I come down with urinary tract infections more frequently.  At the first sign of discomfort, I start with cranberry juice and Azo.  The cranberry juice helps make my urine more acidic (inhibiting bacteria) and the Azo calms my bladder and relieves the urgency and pain.  The only downside (if you want to call it that) is that it turns your urine dark yellow and can stain, but it's definitely worth it)."