Stinky Bathrooms

I have a question. Why, oh why, do public restrooms, especially those in grocery stores, perpetually smell like diarrhea?

I went to the store tonight and suddenly had to take a leak. I opened the door and the smell of hot shit hit me in the face like someone throwing a wet wash cloth over my nose and mouth. A tiny bit of throw-up went into the back of my mouth, but I still had to snap the bean, so one deep breath and in I went.

I suppose, the only people that would actually shit in a public restroom are those that have some sort of mental instability or someone that may have gone on a Coors Light and Taco Tuesday bender the night before, with the latter being the more likely.

I think that a person could clean the bathroom and while the janitor was in there, it would smell like bleach and sunshine and the second, absolute SECOND they walk out, it would instantly smell like hot shit.

I hope someone out there can give me a response to why this phenomena happens. Or maybe not. Maybe I have over thought this one.