i pass the same thing. not a gall stone because i have had my gall blader out for almost 20 years now. it's parasite ovam that is leaving your body. i just had another outbreak of the parasite infestation. it didn't last a year but still makes me quite sick. even after getting the drugs to kill parasites it never left my hair. while experiencing another break out i also passed it again. it was a year before i got those meds and they lay eggs every 21 days. i am severly constipated so those things are still in my body. awful!