Gregg DeGuire, WireImage
Addressing the recent spotlight on his stage-sickness, Justin Bieber explained the cause behind his alarming illness. What is most notable here perhaps, is Bieber's tenacity, he kept right on performing after puking and even apologized to the audience and did an encore. That takes class, and more importantly, a pretty strong stomach. Seems like physical concerns are easier for Bieber to handle than emotional ones, as the singer seems to have found his mom's new tell-all book was tough to swallow.