After one has taken a shit and noticing that it just happens to be the most foul smelling, grotesque looking, massive dirty dump they could have ever taken. This usually follows after one has eaten as much fruit, meat and candy one can.
Jerry: Yo Tony, you'll never believe what happened yesterday.
Greg: I bet I can guess. Only one thing could happen after you ate more than my camel.
Tony: Oh, now I know.
Jerry: It was the meanest poo
i've ever had. The smell knocked out my wife.