Wilko (Dirived from the name of the England Rugby star Jonny Wilkinson) Is a term used for taking a poo. This is because of the stance he takes when he is about to kick the ball, hands grasped legs slightly bent like hes forcing out a fat one.
Courgh someones layed a stonken Wilko in the bog!
Or. I'm off for a wilko, think it was that Rojan Josh!!