Gallstones (cholelithiasis)

Gallstones form when bile becomes supersaturated with cholesterol or bilirubin and crystallises in the gallbladder. Cholesterol stones (~80% in Western populations) are pale and form in obese, female, pregnant, fertile, forty-year-old patients (the classical 'four F's' plus rapid weight loss, oral contraceptives, somatostatin analogues). Pigment stones (~20%) are dark, made of bilirubin, and associate with haemolysis, cirrhosis, biliary infection. Most stones (~80%) are clinically silent and discovered incidentally; about 1–4% per year of asymptomatic carriers develop symptoms. Once symptomatic, the natural history accelerates — biliary colic recurs, and 10–20% progress to acute cholecystitis or stone-induced pancreatitis within years.

• ALT, AST — rise sharply in choledocholithiasis (CBD stone) with peak in the hundreds–thousands.
• Alkaline phosphatase, GGT — cholestatic pattern (markedly elevated) signals obstruction.
• Bilirubin — rises if the stone fully obstructs the CBD or cystic-duct lithiasis with infection.
• Lipase — markedly elevated (>3× normal) in gallstone pancreatitis.
• WBC, CRP — leukocytosis + raised CRP in acute cholecystitis or cholangitis.
• Ultrasound abdomen — primary imaging; >95% sensitive for stones.
• MRCP, EUS — used when CBD stone is suspected but ultrasound is equivocal.

• Biliary colic — severe, steady right-upper-quadrant or epigastric pain after a fatty meal, lasting 30 min – 6 h, often radiating to right shoulder/back
• Nausea, vomiting during colic
• Fever, chills + RUQ pain + jaundice (Charcot's triad — ascending cholangitis, emergency)
• Murphy's sign — inspiratory arrest on RUQ palpation (acute cholecystitis)
• Severe epigastric pain radiating to back, persistent (gallstone pancreatitis)
• Jaundice, dark urine, pale stools (CBD obstruction)
• Most carriers — NO symptoms at all