These white stones as described sound like they are primary enterolith that have formed, usually in the ilium, from mucus. The upper bowel is irritated by something, either dysfunction of lifestyle and is protecting itself with mucus. When this mucus reaches the ilium it precipitates into hard putty like formation.
I had them and showed them to my entero-gastrologist who explained what he thought they were. I was later diagnosed with a condition called CIPO. Note: that is you do have a bowel dysfunction affecting the ilium it will always result in secondary biliary problems because the recirculation of bile as been disrupted.