Another possible contributing factor to the phenomenon is that people are heading outside less, and taking out the trash with less regularity. But according to the City of New York, the only things you should really be flushing are “the four P’s: poop, pee, puke, and [toilet] paper .” Items like condoms, tampons, and paper towels create masses of congealed grease that are costly and difficult (and disgusting) to remove from sewer systems.