Can you please elaborate which type of prostrate surgery? TURP or other? If the patient is having discharge from penis? I couldn't get why u written VDRL ? its the test to see for syphillis. By the symptoms you mentioned it may be urinary tract infection. Since you have already taken medication and have urine tested, further other tests may be necessary. Drink plenty of water. Pleade visit the surgeon where he did surgery if the problem is troublesome. Thank you!