Hello.  I am a 27 year old male and I have trouble emptying my
bladder.  I've had bouts with frequent urination for a while and I was
beginning to suspect that I may have overactive bladder.  In trying to
decide if I wanted to see a doctor about the problem, I started
watching my urination habits a bit and noticed that many times after I
go to the bathroom, a slight urge to urinate comes back within a few
minutes.  If I return to the bathroom, I can sometimes void another
50-100 ml.

A little background; I use the bathroom at most once (sometimes none)
during the night.  I have no problem starting and the flow seems to be
fine.  I have no leaking or incontinence.

So, I'm wondering if my only problem is not properly emptying my
bladder.  Is having some urine retention normal?

Are there any techniques that one can do to help empty the bladder?
Can the muscle the empties the bladder be strengthened?  Can manual
pressure be applied to help empty the bladder?

Any and all comments will be greatly appreciated.
Thank you.
John