Next time you get ready for a flush, you may want to takle some things to soften the stones, to make it easier for them to come down.
When I prepare, a week prior to the flush I include some Lecithins ( 1 Tbsp 3X daily),
I also take Magnesium Malate(1000 mg 2 X daily)
(for the Malic Acid: have a hard time drinking the gallon of apple juice),
Apple Cider Vinegar (I take 1 Tbs in glass of water with molasses and 1/2 lemon),
try eating green apples (Granny Smith is good),
I also drink Kombucha Tea, which I find helps.
Also make sure you eat a light diet for 3-7 day before the Liver Flush.
Don't give up flushing, just be patient.
I've done 14 flushes so far, during my 6& 7 th I got zero out, but then the biggest ones came down after the 10 th flush.