Nygrl.,
Try not to panick until you hear anything definitive from your doctor.
Anxiety can rev the metabolism to the point where you are naturally going to expend nervous energy...and that can = calories out.
By the way...do you have a scale that measure body composition, not just weight?
You could be having a lot of water fluxuation. If you are nervous and urinating more than ususal for instance...what you see in weight loss could actually just be water.
I hope that you get the answers you are seeking soon...keep us posted.
p.s. is the HIDA scan per your's or your doctor's request?
S.C.