At 79, frequent urination is most often benign prostatic enlargement, but I never assume that before ruling out
diabetes and infection. Get these done: urine routine and culture, fasting
sugar and
HbA1c, serum
creatinine, serum PSA, and an ultrasound of KUB with prostate size and post-void residual urine. The PSA should be taken before any per-rectal examination and not after a catheter or urine infection, or the value misleads. A physical prostate examination by the treating doctor still matters along with these reports. If he has burning urine with fever, blood in urine, or is suddenly unable to pass urine at all, that is an emergency the same day. Send me the reports on a Practo consult and I will tell you whether this needs medicines or a urologist.