Understanding Gallstone Causes and Prevention

4. Too Much Bilirubin

Also known as pigment gallstones, these rarer dark-brown-to-black gallstones are formed when our bile contains an excess of bilirubin. Bilirubin is a bile pigment that is formed during the natural breakdown of hemoglobin - more commonly known as red blood cells. If your body is producing an excess amount of bilirubin, there's a chance that you're undergoing problems with your liver. Diseases such as cirrhosis of the liver can be to blame for an excess of bilirubin, but blood disorders and tract infections have been known to cause similar results.

Shidlovski / Getty Images