The fiber absorbed everything instead of letting it come out of the intestines with the diarrhea. You should try next time without the fiber. Just take the recommended doses of Epsom Salt like most people do here and you'll see the stones come out in the morning. For some people, the stones come out the evening of the flush.
I wanted to give you a tip how to take the epsom salt. Dissolve a tablespoon of the ES in a bit of apple juice and drink it quickly. If you warm up the juice a bit it will help dissolve the salt. After you drink it, drink a large glass of water. You'll never taste the Epsom Salt this way.