since your father is 59 he may have mildly enlarged prostate
which is common in most males above 50 .1-2; pus cells 3-4 RBC
; cannot be called a bad infection .Ask him if he has weak flow of urine;also does it take sometime & some effort during start of urine;if yes he may have prostate enlarged.But prostate does not cause severe pain
;if the pain is severe then it can be a very small stone which can be missed on ultrasound
.Please let me know this to help you better.