busting a gut

Busting a gut is a cliche often used as a way to say you are working very hard, often to the point where you are straining yourself in order to accomplish something. This is a figurative phrase in which you are physically working extremely hard which may be tough on your body and can cause physical strain and abuse from the work. Busting a gut may also be used in instances where you work hard, not necessarily physically but emotionally as well.