Pigment gallstones are most commonly seen in the developing world.

"Bile and stone analysis in two infants with brown pigment gallstones and infected bile".

An analysis of two infants suffering from cholelithiasis observed that a substantial amount of stercobilin was present in brown pigment gallstones.

This study suggested that brown pigment gallstones could form spontaneously in infants suffering from bacterial infections of the biliary tract.

Infected bile, pigment gallstones, male gender, advanced age, perihepatic location of spilled gallstones, more than 15 gallstones and an average size greater than 1.5 cm have been identified as risk factors for complications.