04/01/2026
Bile is a digestive liquid made by the liver and stored in the gallbladder. It helps digest fats.
Gallstones form when bile doesn’t flow or mix properly.
Main ways gallstones form
1. Too much cholesterol in bile (most common)
The liver releases excess cholesterol
Bile cannot dissolve all of it
Cholesterol crystals form
Crystals grow and harden into stones
2. Too much bilirubin
Bilirubin comes from the breakdown of red blood cells
Certain conditions cause excess bilirubin
It combines with calcium → pigment stones
3. Gallbladder doesn’t empty fully
Bile stays too long in the gallbladder
It becomes concentrated
Crystals have time to form and grow
Types of gallstones
Cholesterol stones – yellow-green, most common
Pigment stones – dark brown or black, less common
