I took 3 courses of bactrim in the last 2 months but the infection returns. i can't take cipro (ciprofloxacin) and nitrof didn't work. my urine tests vere negative. the urologist is treating me symptomatically. what should i do?

Infection?: Has a urine culture ever come up positive for a particular organism? Do you get symptomatic relief when you take the bactrim, (sulfamethoxazole and trimethoprim) and then do the symptoms come back? What are your symptoms? I am not a urologist, but this sounds a little strange. Hopefully a urologist here can weigh in.

Culture: If the urine tests are negative or normal, then i would start to suspect something else and not "infection". Cystitis is a bladder inflammation that feels just like and infection and is a miserable problem. Interstitial cystitis would be a possibility. But if you are saying your infection returns, then investigation into why would be next.

Be careful...: Several courses of antibiotics - was there a workup for the cause of your symptoms? If not, i would re-evaluate your situation to determine if there is a problem that is ability to void completely and without problems . In your case, the multiple courses of abx without determining the cause will eventually lead to multi-drug resistant bacteria.