Urinary symptoms in elderly men may largely be divided into irritative (frequency and urgency) and obstructive (taking time to pass urine, interrupted stream, feeling of incomplete evacuation in nature. While obstructive symptoms may be attributed directly to obstruction following prostate enlargement, irritative symptoms may or may not be due to prostate. Up to 70% men and women (and women do not have prostate) may have urinary irritative features in form of night frequency due to bladder irritability by the age 70.There are many medical conditions like uncontrolled diabetes and cardiac failure which may result in frequency. There are possible complications following prostate surgery too which may worsen the urinary frequency, especially failure to empty the bladder with large residual urine. In conclusion, your urinary frequency after prostate surgery could be due to a medical condition, an irritable bladder or a result of the surgery itself. You need to see your urologist who would go into details of your voiding pattern including voiding diary, and examine you. He may like to have some blood investigations and urine examination to exclude infection, flow test to judge the degree of obstruction, apart from an ultrasound of the KUB region to evaluate efficacy of bladder emptying. Having done this it will be possible to put a label to your problem of frequency and treat it appropriately.