There is still time for the stones to come out.I have done flushes where the stones did not appear until late afternoon. They can be buried inside the feces, so I would suggest that you inspect your bowel movement thououghly! I actually shit in a collander and then as I flush the toilet, I shake the collander. The stones stay and the rest is flushed so you can see the stones. If you really do not want to do this, at least poke around with a chop stick or some other disposable tool.