I recently finished remodeling a bathroom for a client and he has noticed a pungent odor. The bathroom has a walk-in shower, no tub. Floor and walls are tiled in honed limestone. The bathroom has been used daily (including showers) so all drains are primed and it also sits over an unfinished basement so I know there are no leaks. I have also run a camera thru the vanity drain to make sure I didn't leave a cap off a vent or something and everything appears to be perfect. I have never smelled anything in this bathroom and I am confident it is not sewer gas. Any clues?