We tend to use "he's just past Upton Park".
Or shorten it to West Ham, Upton or East Ham depending on how insane.
( The Teviot Moose major 5th., Fri 12 Jan 2007, 13:34, archived)

My brother used to say
"I'm off for a Duncan Ferguson" when he was off for a shit.
(rnuk http://flickr.com/rnuk, Fri 12 Jan 2007, 13:37, archived)