One frequently visits the lanes of anothers rectum with the use of his nicely shined bowling balls. Unlike traditional bowling, however, the goal is to get ones balls as deep into the gutter as they can. Usually denotes a raging homosexual. San Francisco is well known for it's professional colon bowling league.
"Did you see that guy? He was obviously a colon bowler!"
"Hey, you think Toms a colon bowler?"
"No, I heard he's got a hot girlfriend."
"Dude, don't touch my ass! What are you a fucking colon bowler?!"