How do I get the jewel back after it's been taken?

Hint 1 of 3:

OK, it's a polite fiction -- it's been eaten by Momma.  Where does a jewel go
after it's been eaten by a Mother Hungus?

Hint 2 of 3:

No, not in the Hungus' bathroom -- it's in her stomach.  Do you have any
magical items that would get something out from a Hungus' stomach?

Hint 3 of 3:

You'd need something to turn it inside-out.