Aha ... someone clearly griped to the Observer ... from their 'corrections' column:

'Don't blame the drink; blame the pressure to drink' (Opinion, last week) referred to city-centre bars 'which turn into vomitoriums at mignight'. Far from being a place to be ill, a vomitorium is actually an architectural feature, a passage situated below or behind a tier of seats in an amphitheatre, through which the crowds could 'spew out' at the end of a show.