GastroenterologyTier 1Disease (DEADMAN)

Gallstones

Description

Cholesterol stones (~80%) - most common in Western populations; pigment stones (~20%) - black (haemolysis, cirrhosis) or brown (biliary stasis/infection)
Spectrum of disease from asymptomatic (majority) -> biliary colic -> cholecystitis (gallbladder inflammation) -> choledocholithiasis (CBD stone) -> cholangitis (infected obstructed biliary tree) -> gallstone pancreatitis - each a distinct clinical entity with escalating urgency

~10-15% of adults have gallstones; majority remain asymptomatic lifelong
Classic risk profile - "Fat, Female, Forty, Fertile" - obesity, female sex, age, and parity/oestrogen exposure
Only ~1-4% per year of those with asymptomatic stones become symptomatic

Cholesterol stones

Cholesterol supersaturation of bile (relative to bile salts/lecithin) -> crystallisation -> stone formation
Risk factors: obesity, rapid weight loss, oestrogen (pregnancy, OCP, HRT), age, female sex, FHx, T2DM, fibrates

Pigment stones

Black - chronic haemolysis (spherocytosis, sickle cell), cirrhosis - excess unconjugated bilirubin
Brown - biliary stasis and infection (E. coli, bacterial beta-glucuronidase deconjugates bilirubin) - associated with strictures, parasitic infection (in endemic areas)

Progression to complications

Stone impacts cystic duct -> biliary colic (transient) or acute cholecystitis (persistent obstruction + secondary inflammation/infection)
Stone migrates to CBD -> choledocholithiasis -> if infected, ascending cholangitis; if it obstructs the pancreatic duct outflow -> gallstone pancreatitis

Clinical spectrum

Entity	Features
Biliary colic	RUQ/epigastric pain post-fatty meal, <6h, resolves spontaneously, no fever/systemic signs
Acute cholecystitis	Persistent RUQ pain >6h, fever, Murphy's sign positive, may have mild LFT derangement
Choledocholithiasis	Obstructive jaundice pattern (raised bilirubin/ALP/GGT), +/- pain
Cholangitis	Charcot's triad (fever, jaundice, RUQ pain) +/- Reynolds' pentad (+ hypotension, confusion) if severe
Gallstone pancreatitis	Epigastric pain radiating to back, markedly raised lipase, gallstones on imaging

Investigations

Ultrasound - first-line for all (stones, gallbladder wall thickening/pericholecystic fluid in cholecystitis, CBD dilatation)
LFTs - obstructive pattern (raised ALP/GGT/bilirubin) suggests CBD involvement
MRCP - non-invasive definition of CBD anatomy/stones if ultrasound equivocal
ERCP - both diagnostic and therapeutic for confirmed/high-probability CBD stones

A. Asymptomatic gallstones

No treatment required - incidentally found stones do not need prophylactic cholecystectomy in the general population

B. Biliary colic

Analgesia, dietary fat modification; elective laparoscopic cholecystectomy given high recurrence risk

C. Acute cholecystitis

Early laparoscopic cholecystectomy (within 72 hours-1 week of symptom onset, ideally during the index admission) - preferred over delayed surgery regardless of exact symptom duration per Tokyo Guidelines
IV antibiotics if signs of infection/systemic inflammation
Percutaneous cholecystostomy for patients too unwell/high-risk for surgery, with interval cholecystectomy once stabilised

D. Choledocholithiasis

ERCP with sphincterotomy and stone extraction, followed by (usually same-admission) cholecystectomy to prevent recurrence

E. Ascending cholangitis - emergency

IV antibiotics + fluid resuscitation immediately
Urgent biliary decompression (ERCP first-line) - definitive treatment, do not delay for antibiotics alone to work; percutaneous transhepatic drainage if ERCP fails/unavailable

F. Gallstone pancreatitis

Supportive pancreatitis management (see pancreatitis note); ERCP within 24-48h if cholangitis or ongoing biliary obstruction present
Cholecystectomy during the same admission (once pancreatitis settling) - reduces recurrence risk, per current evidence favouring index-admission surgery over delayed

Obesity, rapid weight loss (including post-bariatric surgery), pregnancy, OCP/HRT
Haemolytic disease (pigment stones), cirrhosis
T2DM, family history, older age, female sex
Total parenteral nutrition, prolonged fasting - biliary stasis promotes stone formation

Most gallstones remain silent lifelong; once symptomatic, recurrence of biliary colic is common without cholecystectomy
Untreated acute cholecystitis - risk of gallbladder gangrene/perforation, empyema
Cholangitis - can progress rapidly to septic shock if biliary decompression delayed
Gallstone pancreatitis - recurrence risk is high without cholecystectomy, which is why same-admission surgery is now favoured over a delayed "interval" approach
Chronic gallbladder inflammation (porcelain gallbladder) - rare but associated with increased gallbladder cancer risk, sometimes prompts consideration of prophylactic cholecystectomy

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