What is butt chugging?

From MTV films' Jackass

It's direct absorption of alcohol (bypassing the liver) vaginally or rectally and it's dangerously stupid. A denial of the practice by the attorney of a Tennessee frat boy who was admitted to a hospital for alcohol poisoning ("well over .40") went viral today. The attorney simultaneously called the accusation of said activity by his client a lie and castigated the hospital for leaking details of the kid's medical records.
     The righteously indignant counsel said nothing about the police report containing the conclusion he so strenuously denied; video of his surreal press conference immediately got world-wide attention on the Internet.
     The attorney and/or his client are evidently so stupid and/or homophobic that he/they felt the need to issue an irrelevant denial-of-homosexuality disclaimer at the beyond-strange press conference.