A chronic condition by which the physical connections between the buttocks and head are reversed, causing fecal material to spew from the mouth. Conventional treatments include wiring the jaws shut or the prompt use of a gag ball.

ACIS is more harmful to those coming in contact with the ACIS person than the ACIS person him/herself. Even casual contact results in looks of disbelief, screaming and the uncontrolable urge to place one's hands over one's ears and yell "Make it stop". Family and friends living with an ACIS patient are advised to wear ear plugs, or in more extreme cases, to drive shiskabob spears through their ears.

Not to be confused with having Head-Up-Assitisis or Asshatoses.

n. temporary state of having ones head in ones ass or other orifice.

Etymology: cranial- of or relating to the cranium or bones that encase the brain; Greek in origin. + Suppository- easily melted solid placed in a body cavity or passage; Latin in origin.

Windows of opportunity for enhanced vision providing unique novelty picture frames that help the inverted person see where they are going.

Anal Cranial Inversion: One's head lodged firmly up into their rectum.