Seriously need Help! What am I????

So last night my son came up to my husband and told him that our 17 month old daughter swallowed a battery. What? How on earth would she have done that? So after calling around and realizing there was no way for a baby to swallow a AA battery, we decided to wait and see. I was talking to my sister this morning and she told me to take her right away, just to know for sure. Poison control said the same thing. So off to the ER we went at 10 am this morning. Have you ever been to the ER with two young kids. Lots of fun. So they took an x-ray and said there was no battery, but what looked like a button or something. They ordered more x-rays and the doctor called me out of the room. He took me to the computer to ask me if maybe I knew what it was that she swallowed. I expected to know right away, but I had no clue. So here I am all puzzled, knowing that my daughter has something in her body, but no idea what. I won't know until she passed is. The doc said it's already made it's way through her intestines and now it's in the colon. So now we wait and see. Can you tell from the pic what it is?