A small quick forced hard fart from
the bottom flowing strong out of the feicy hole.
To achieve 'Anal Cough' you needa really clench those anus cheeks like your life depends on it but dont fear. This double acts as a wall blocking any
follow through.
Now push that bodily gas as hard as you can toward the
poop hole. It should sound as if you are letting air out of a very large blown up balloon.
Everyone will laugh and should be able to smell it