damob
Here's a thought. I know one possible side effect listed for hydo is urinary retention. I have the same experience as you do. I think that when on hydro you retain or keep more urine. You feel the need to go so often because there is more urine being stored. When the bladder contains a certain amount nature calls. You and I may think we are emprtying our bladders with each bathroom visit, but actually keeping a lillte each time. Thus we feel the need more often to get up and go.It is a diificult thing to be able to tell there is a change in the amount of each urination, but this would be my guess.
Or then again it could be a simple urinary tract infection.
JMO
-K-