I'm not sure that there ARE any effective medicines available for that - all the procedures I've personally heard about involved surgery (including sewing cadaver skin to the penis to increase the girth).
Most "medicines" are just scams to wrest money off the desperate - most of the pills are just testosterone, vitamins and herbal supplements. I don't think there IS anything truly effective and medical which will "grow" the penis at all - if only because it'd have been publicised a LOT better if there was.
Mind you, I doubt this will be the first time your urologist has been asked about this sort of thing, and he's by far the expert.
Anyway, I agree with Ambi. *nods* It shouldn't matter what size you are, if you're in a meaningful relationship with someone.