What Causes Urinary Frequency With Burning Sensations?

Hello, My age is 53, wt-59 kg, menopause-from last one year, i am anaemic, lack of calcium,blood sugar normal, not diabetic, normal BP.having problem in urination, feeling burning sensation, not able to control its pressure, frequent urination, that has happened earlier in april.2011,then doctor suggested me for urine culture and diagonsed e.coli, some anti bacterial medicines-ceftum.it got clear by june.and from last 2 days i am suffering from the same problem.i need to understand from you what are the possible reasons for its relapse and what could be the repercussions of it.is it curable? right now i am taking norfloxacin as suggested by the doctor, so can i go for urine culture in this condition-while taking norfloxacin,which is an antibiotic....kindly respond..ASAP...