64 yo male hospitalized 3 months can now stand & walk but cannot urinate standing, just sitting using a pee bottle or sitting on the toilet. ideas?

Interesting: It is usually the other way around. Has a urologist been involved? Were urodynamic studies done including post void residuals, flow measurements and bladder pressure measurements along with good neurological evaluation from the lumbar spine down including the sacral plexus nerves. I know this is medical speak, but discuss these with treating doctor. Complicated issue and needs proper eval.