swallowed metal object

Question
My nieces pig pulled a metal ring about the size of a pencil eraser off of something and swallowed it. Talked to the vet, need to wait and see if it makes it through the intestine.  It is a closed ring with no rough edges.  Is there anything we can give him to help him pass it successfully?

Answer
Well i suppose soemthing that gives him the runs might help, in which case citrus fruit. but... citrus is bad for a guinea pig. I am very surprised that he ate something that size though and you will have to make sure that he doesn't et it again afterwards as they ate their first poo like rabbits. perhaps cranberry juice might help as well, it wont do any harm to give him that in a water bottle.
best of luck.