What types of gallstones are commonly encountered?

• A. Cholesterol stones
• B. Pigment stones
• C. Cholesterol stones and pigment stones
• D. Calcium oxalate stones

Answer: (C)

The main idea here is understanding what gallstones are made of and which forms you’re most likely to see in practice. Most gallstones come in two common types: cholesterol stones and pigment stones. Cholesterol stones form when bile becomes saturated with cholesterol or when substances that keep cholesterol dissolved (bile salts and phospholipids) are reduced. They’re by far the most frequent type seen. Pigment stones arise from bilirubin pigments precipitating in bile; they’re often tied to conditions that increase bilirubin or cause biliary infection, and they’re also commonly encountered. In contrast, calcium oxalate stones are kidney stones, not gallstones, so they don’t belong in the gallbladder stone category. Therefore, cholesterol stones and pigment stones together account for the majority of gallstones you’d expect to encounter.