Your pretty gross example covers all the toilets on several university campuses I've been to as well. Very common
They s shaped pipe hasn't been invented there yet (things may have changed in the past ten years though, but certainly not all bathrooms have been remodeled that quickly) and so the sewage pipes regularly blast out burps of stinky poo smells into the restrooms. This happens in student dorm rooms too if you have the top tier ones that have a private toilet for the room as opposed to a huge communal one.
They s shaped pipe hasn't been invented there yet (things may have changed in the past ten years though, but certainly not all bathrooms have been remodeled that quickly) and so the sewage pipes regularly blast out burps of stinky poo smells into the restrooms. This happens in student dorm rooms too if you have the top tier ones that have a private toilet for the room as opposed to a huge communal one.