From the Guidelines
Gallbladder stones are primarily classified into three types: cholesterol stones, pigment stones, and mixed stones.
- Cholesterol stones are the most common type, comprising approximately 80% of all gallstones, and are typically composed of cholesterol crystals 1.
- Pigment stones are often associated with hemolytic disorders and may require cholecystectomy 1.
- Mixed stones contain both cholesterol and pigment components and may be managed with a combination of treatments, depending on the individual patient's condition and stone composition 1. The provided evidence does not specify the exact composition or treatment options for each type of stone, but it does mention that nonsurgical therapy, such as oral bile acids, can dissolve cholesterol stones by increasing the cholesterol in bile 1. However, the use of bile acids is limited to gallstones with a diameter less than 1.5 cm and whose content is primarily cholesterol 1.
From the FDA Drug Label
Although liver injury has not been associated with ursodiol therapy, a reduced capacity to sulfate may exist in some individuals, but such a deficiency has not yet been clearly demonstrated. The various actions of ursodiol combine to change the bile of patients with gallstones from cholesterol-precipitating to cholesterol-solubilizing, thus resulting in bile conducive to cholesterol stone dissolution. Complete stone dissolution can be anticipated in about 30% of unselected patients with uncalcified gallstones < 20 mm in maximal diameter treated for up to 2 years Patients with calcified gallstones prior to treatment, or patients who develop stone calcification or gallbladder nonvisualization on treatment, and patients with stones > 20 mm in maximal diameter rarely dissolve their stones.
The types of gallstones are:
- Cholesterol stones: These are the most common type and are responsive to ursodiol therapy.
- Calcified stones: These are less common and are not responsive to ursodiol therapy. There is not enough information in the label to determine if there are other types of gallstones. 2
From the Research
Types of Gallstones
- Cholesterol stones: the most common type of gallstone, formed when there is an imbalance in the composition of bile, resulting in the precipitation of cholesterol [ 3, 4,5,6,7 ]
- Pigment stones: divided into black and brown pigment stones, formed when there is an imbalance in the composition of bile, resulting in the precipitation of bile pigments [ 3, 4,5,6,7 ]
- Mixed stones: stones with two or more types of material components, including cholesterol, pigment, and other substances [ 3, 4 ]
- Calcium carbonate stones: a type of gallstone formed when there is an imbalance in the composition of bile, resulting in the precipitation of calcium carbonate [ 3 ]
- Phosphate stones: a type of gallstone formed when there is an imbalance in the composition of bile, resulting in the precipitation of phosphate [ 3 ]
- Calcium stearate stones: a type of gallstone formed when there is an imbalance in the composition of bile, resulting in the precipitation of calcium stearate [ 3 ]
- Protein stones: a type of gallstone formed when there is an imbalance in the composition of bile, resulting in the precipitation of protein [ 3 ]
- Cystine stones: a type of gallstone formed when there is an imbalance in the composition of bile, resulting in the precipitation of cystine [ 3 ]
Classification of Gallstones
- The systematic classification of gallbladder stones indicates that different types of stones have different characteristics in terms of microstructure, elemental composition, and distribution [ 3 ]
- Gallstones can be classified into 8 types and more than ten subtypes, including cholesterol stones, pigment stones, calcium carbonate stones, phosphate stones, calcium stearate stones, protein stones, cystine stones, and mixed stones [ 3 ]