A phantom shit is the rare phenominon wherein a shit (usually of a solid, well-defined mars bar-like constitution) disappears entirely from sight before the shitee has a chance to admire his creation. A phantom shit completely submerges itself beneath the upper waters of a toilet-bowl in an instant.
Initially such an occurence brings on the sensation of euphoria. However, the bliss is quickly replaced by paranoia and self-doubt as one tries to recall if they did truly shit or not. Usually the doubt can be subdued by wiping ones ass and finding shit upon the toilet paper. However, if the shit was a clean run and the toilet paper produces no shit-stains, then symptons may intensify until the shitee becomes a paranoid retard who believes in, and creates, conspiracy theories.
-Bob squats over his toilet and unleashes a dump
-Bob rises to a stand and stares down at the toilet to find it empty. A phantom shit has occured.
-Astonished, Bob grabs for some toilet roll in a panic and wipes his ass
-The toilet roll produces no shit post-wipe and Bob runs away from the bathroom flailing his hands above his head whilst screaming
-Bob tells his friends that The Illuminati are in cahoots with giant-headed aliens in a plot to take over the world.
-Bob creates retarded websites and spends his life masterbating over sexless, fictional alien creatures.