If you don't pass all the stones right away...you will pass them the next day or the next...they will eventually come out! BUT, in my experience, you really do want to get them out right away because they smell horrible if left to melt inside your bowel! ick. The stones I've seen on Day2 are usually just a crispy shell...and inside, nothing, totally hollow...only a bit slimy. (sorry for the gorey details)