Check the Jerusalem artichoke episode
http://m.youtube.com/watch?v=9aHl5fY_VzQ&feature=plpp&p=PLP7CpMQFBDG6GYSQnN6Dr3tr3IBEAGgKz
I have seen jchokes in a lot of documentation. Those roots go back. As a use as a flour it is a super food. Flatulence perhaps comes if you are detoxing something that needed to be moved out. It's okay, let it go. Jerusalem here is a colonial times form of Girasole. Italians word for sunflower.
