Which of the following is the most common type of gallstone found in the Indian population?

Explanation

## Gallstone Classification and Epidemiology ### Types of Gallstones | Stone Type | Composition | Prevalence in India | Risk Factors | |---|---|---|---| | **Cholesterol stones** | >50% cholesterol monohydrate | **Most common in India** | Female, fat, forty, fertile (4 F's) | | Pigment stones (black) | Unconjugated bilirubin + calcium | Less common | Hemolysis, cirrhosis | | Mixed stones | Cholesterol + pigment | Variable | Combined risk factors | | Calcium bilirubinate (brown) | Calcium salts of bilirubin | Rare | Biliary infection, parasites | ### Geographic Variation **Key Point:** Cholesterol stones are the **most common type of gallstone globally and in the Indian population**, accounting for approximately 70–80% of all gallstones. While there is a historical teaching that pigment stones predominate in Asia, contemporary Indian surgical literature (Bailey & Love's Short Practice of Surgery; Sabiston Textbook of Surgery) confirms that cholesterol stones are now the most prevalent type in India as well, driven by dietary westernization and rising obesity rates. **High-Yield:** Risk factors for cholesterol stones (the "4 F's"): - **F**emale sex (estrogen increases cholesterol secretion) - **F**at (obesity increases hepatic cholesterol secretion) - **F**orty (increasing age) - **F**ertile (multiparity, oral contraceptive use) **Clinical Pearl:** Pigment stones (black and brown) are associated with hemolytic anemias, cirrhosis, and biliary infections, and are more common in East Asian populations with high rates of parasitic biliary infections. However, in the Indian subcontinent, cholesterol stones predominate overall. **Warning:** Older Indian surgical texts sometimes cited pigment stones as more common due to higher rates of hemolytic disease; however, current epidemiological data and standard surgical references confirm cholesterol stones as the most common type in India. --- *Reference: Bailey & Love's Short Practice of Surgery, 27th edition; Sabiston Textbook of Surgery, 20th edition.*