We have a new intern in the Montreal office and he’s a hard-working,
research-oriented, serious guy. So we asked him, “Michael, are farts
air-poop?” And he said, “I’m not sure but I could find out” so we said,
“Why don’t you?” and he said, “Do you want that by Thursday?” and we said, “Sure, Thursday would be fine.” And then on Thursday he sent us his answer:

“This is an interesting question. First we need to define the two
processes. Farts and poo are both created in the large intestine. Poo is the by-product of digested food. In part, farts are a by-product of that process. Undigested
foods that make their way to the intestine can create gas, but farts
are also produced by gases that your body no longer needs, such as
nitrogen or carbon dioxide.

So, on the one hand, farts and poo are closely related to each other because
they are produced by similar means and transferred the same way. But
they are, in fact, two separate things. Farts are the dispersement of
wasteful gas in the body and therefore not poo. 

But as to the question of whether farts contain
poo. Farts are just gas. But since both poo and farts inhabit the
same neighborhood it goes without saying that if gas is going through
your sphincter it can pick up and collect poop molecules, and in that way, you could argue that farts are air-poop.”

MICHAEL CHADWICK