Thanks for visiting HCM.
Let me assure you that rifampicin do not cause urinary tract irritation
. It usually cause orange coloured urine
which is due to metabolite of drug passing in the urine, and is harmless.
Your symptoms may be a problem with prostate like benign prostatic hyperplasia
or it's just simple urinary tract infection
...both of which has nothing to do with rifampicin or isoniazide which you are taking.
I advise you to go for urine examination (routine microscopy and culture and sensitivity) and ultrasonography
of abdomen to look for prostate. And above all continue with your anti tubercular treatment.
Consult your doctor with above reports.