An act in which one lubricates the neck of a beer bottle then fully sits on it so it completely enters that person anally. They then lean forward, lifting the bottle upwards so the contents flow into their anal cavity. The bottle is then removed and the contents are sprayed from the anus. This also produces a quick alcohol buzz compared to drinking the beer. Also related to the term, "beer enema cocktail" in which someone drinks the beer after it has been used as an enema.
Sally didn't want to have "beer breath" so she had several beer enemas at the party.