Understanding Gallstones: Types, Causes & Symptoms

Gallstones, also called cholelithiasis, consist of digestive fluids that form into hard, pebble-like deposits in bile. A majority of gallstones form in the gallbladder. Gallstone sizes range from as tiny as a grain of sand to as big as a golf ball.

Cholesterol Gallstones

• Cholesterol gallstones are the most common type of gallstones. These yellow gallstones consist primarily of undissolved cholesterol.

Black Pigment Gallstones

• Black pigment gallstones form when the bile contains an excess of bilirubin, a pigment in blood that passes through the liver. The bilirubin combines with calcium to form black gallstones.

Brown Pigment Gallstones

• Brown pigment gallstones form when bacteria alters the bilirubin in the gallbladder. The altered bilirubin then combines with calcium and fats to form dark brown gallstones.

Ceftriaxone Gallstones

• Patients taking the ceftriaxone antiobiotic occasionally form gallstones. The medication combines with calcium in bile to develop hard deposits.

Risk Factors

• Individuals with diabetes and cirrhosis are more likely to have stones form in their gallbladders. Gallstones are also more common in Native Americans, females and individuals older than 40.