A safer and trendier way of saying bullshit, can be used around teachers, children and elderly people without fear of getting done for anti-social language.
Child: My young mind remains unsoiled due to your use of the word bullsh
Also 'I call bullsh' - Meaning to say if one of friends makes an outlandish statement that you don't believe.
Dude: So I left the club with the hottest chick there.
Man: Pfft, I call bullsh!