I had a TUIP two months ago and had my follow up with my Uro last
week.  Obstructive symptoms are greatly improved but irritative
symptoms remain due to bladder functionality developing over the
years.

Bladder retraining is precisely that: If you've had a weak flow due to
obstruction for years your bladder will adapt to it.  Even when the
onstruction is removed your bladder can still think it's there and
continue to try and push urine out in the same way.  Over time -
provided there is no lasting damage to the muscular tone - it will
learn that it's gone but that can take over a year.  Bladder training
speeds this up by forcing your bladder to get into new habits.  I've
just started it and it's tough at times but less than a week later I'm
already noticng some slight differences.

Here is a good leaflet explaining it:

http://www.gloshospitals.org.uk/ppi/leaflets/pdf/GHPI0534.pdf

Regards.

M.