i thought the same about my liver...but as i found out on flush 6 i have tonnes of stones in there and i have barely begun to get them out.
i think that some people take longer to respond...i started cleansing for fun and to see what would happen...i wasn't in pain and having good bm's. for the last 5 months i eliminated a zoo of parasites (most of my Liver Flushes produced new and different worms each time!!!), did a master cleanse which resulted in plaque and a few ropes...and finally the last liver cleanse produced some beach glass looking stones.
so, to sum it up, unless you fast 2wice a yr and live a pristine lifestyle you will have stones/worms and intestinal gunk accumulated. and if you don't i envy you!!! ;-P
i'd say keep flushing - if you are like me, you will see good results by 5th flush if not sooner!
also make sure you know what to look for or you will miss them!