Fingers crossed that Ruby hasnt actually swallowed the screw and maybe dropped it when she realised the commotion,
Iv seen this happen with Riley, and Ive found the said item later, I know you,ve looked for it, but these things have a strange habit of hiding very well when we need to find them most.
If she has then really hope it passes quickly, It should be out this morning , so keep a beady eye on that poop.
Let us know how it goes.