Alf,
A lot of people have used Flomax for that purpose and I tried it but it did not work for me. Dr. told me if it was effective I would know within 1 week. Destrol or Detrol was the other he mentioned but he said he had side effects and I told him I would wait. My urologist then gave me a two weeks worth of a new product that you rub on your body, Gelnique, but not sure it even helped. It has taken over 2 months post rad for me to be back around normal, but I am probably an exception as most men have taken far less time.
Hang in there as it is a pain in the neck but should resolve itself, but you just might try flomax for 1 week to see if it make a difference.
Michael