What are some possible causes for pigment Gall stones

Hi, I recently had my gallbladder out. This was after they were seen on ultrasound and the Hida scan didn't show the gallbladder even with the morphine injection. The pathology report diagnosis was 'chronic cholecytitis' and 'cholelithiasis' (smooth black stones). I'm assuming from the color that they are pigment stones (I have photos).

Are there any further (blood etc) tests to detect what caused the formation of these particular type of stones? Or any analysis of the gallstones themselves. Pigment stones are supposedly less common amongst the types and my gallbladder was full of them.

Anyone else here have pigment type stones?

Thanks

[CalGal]

Pigment stones purported result from increased hemolysis - more bilirubin - or in some cases liver issues. If the stones were ductal, it has been suggested they can result from a bacterial infection.

This is something you may want to discuss with your doctor. He knows your system and can put all the results of all your tests together to come up with a yes or no about doing further testing.