[Sethomas]

Feces contains trillions of e. coli bacteria per cubic inch. Granted there are probably hundreds of strains of e. coli, you're not immune to the stuff that dwell happily in your lower intestines. In fact, if you get a wound in your lower intestines, the bacteria will seep outwards and require tons of antibiotics, probably killing you regardless in the end.

So, if you eat enough human shit, even your own, you will die of septic shock. This would probably entail death by fever under a weakened immune system on account of dehydration after you can no longer digest food properly and you shit yourself crazy.