Key Facts

Gallstones are extremely common and represent a significant burden on healthcare systems. While most remain asymptomatic, symptomatic stones can cause significant morbidity and life-threatening complications.

Epidemiology

Prevalence is 10-15% in UK adults. Female predominance (2:1). Increases with age — >25% of women >60 years. Annual incidence of symptoms in stone carriers is ~1-4%. Over 70,000 cholecystectomies are performed annually in England.

Aetiology

Cholesterol stones (80%):

• Supersaturation of bile with cholesterol (relative excess of cholesterol vs bile salts and phospholipids)
• Risk factors: obesity, oestrogen (female sex, OCP, pregnancy), rapid weight loss, fibrates, diabetes, Crohn's (bile acid malabsorption)

Pigment stones (20%):

• Black (haemolytic): chronic haemolysis (sickle cell, spherocytosis, thalassaemia), liver cirrhosis
• Brown (infection-related): biliary infection, parasites (Clonorchis, Ascaris), biliary stasis

Pathophysiology

Cholesterol stones form when bile becomes supersaturated with cholesterol. Gallbladder hypomotility (stasis) and nucleation factors promote crystal formation and stone growth. Stones may remain in the gallbladder (causing biliary colic if impacted in cystic duct) or migrate into the CBD (choledocholithiasis), causing obstructive jaundice, cholangitis, or pancreatitis.

Biliary Colic

• Constant RUQ/epigastric pain (misnomer "colic" — pain is steady, not intermittent)
• Duration 30 minutes to 6 hours (if >6 hours → suspect cholecystitis)
• Often post-prandial, especially fatty meals
• Radiation to right scapula/shoulder
• Nausea, vomiting
• Normal inflammatory markers, no fever

Complications

• Acute cholecystitis: persistent RUQ pain >6 hours, fever, Murphy's sign
• Choledocholithiasis: jaundice, dark urine, pale stools, raised ALP/bilirubin
• Ascending cholangitis: Charcot's triad (fever/rigors, jaundice, RUQ pain); Reynolds' pentad (+ confusion, hypotension = severe sepsis)
• Gallstone pancreatitis: epigastric pain radiating to back, raised lipase

Red Flags

• Fever with rigors and jaundice (cholangitis — septic emergency)
• Persistent severe RUQ pain with peritonism (perforated gallbladder/empyema)
• Painless jaundice (consider head of pancreas tumour, not just CBD stone)

Bedside

• Observations: temperature, pulse, BP
• Murphy's sign: positive in cholecystitis (inspiratory arrest on RUQ palpation during deep breath)

Bloods

• FBC: leucocytosis (cholecystitis, cholangitis)
• CRP: raised in cholecystitis/cholangitis
• LFTs: ALP/GGT raised (obstructive pattern) if CBD stones; ALT may be transiently raised (stone passage)
• Bilirubin: conjugated hyperbilirubinaemia in CBD stones
• Amylase/lipase: raised if gallstone pancreatitis
• Blood cultures: if cholangitis suspected

Imaging

• USS abdomen: first-line — gallbladder stones (>95% sensitivity), wall thickening (>3 mm suggests cholecystitis), pericholecystic fluid, CBD dilatation (>6 mm suggests choledocholithiasis)
• MRCP: gold standard for CBD stone detection — sensitivity >95%
• CT: for complications (perforation, abscess, pancreatitis)

Special Tests

• ERCP: diagnostic AND therapeutic for CBD stones — sphincterotomy + stone extraction; NOT for diagnosis alone (invasive, complication risk 5-10% including pancreatitis)
• EUS: highly sensitive for small CBD stones; alternative to MRCP
• HIDA scan (cholescintigraphy): if acalculous cholecystitis suspected or functional gallbladder disorder

Non-pharmacological

• Asymptomatic gallstones: no treatment — reassurance; "leave well alone" (annual risk of symptoms only 1-4%)
• Dietary: reduce fatty food intake (may reduce attacks but does not dissolve stones)

Pharmacological

• Biliary colic analgesia: diclofenac 75 mg IM (first-line — reduces pain AND reduces progression to cholecystitis); paracetamol, opioids if needed; buscopan (hyoscine butylbromide) 20 mg IV for spasm
• Ursodeoxycholic acid (UDCA): 8-12 mg/kg/day; dissolves small cholesterol stones (<10 mm) in functioning gallbladder; rarely used (slow, high recurrence); mainly for those unfit for surgery

Surgical/Interventional

• Laparoscopic cholecystectomy: gold standard for symptomatic gallstones; same-day or next-day surgery for uncomplicated biliary colic is safe; for cholecystitis — early (within 72 hours) preferred over delayed (ACDC trial, CHOCOLATE trial)
• ERCP + sphincterotomy: for CBD stones — before or during cholecystectomy
• Intraoperative cholangiogram (IOC): to identify CBD stones during cholecystectomy
• Cholecystostomy (percutaneous gallbladder drain): for acute cholecystitis if patient unfit for surgery (sepsis control; bridge to cholecystectomy)

Referral Criteria

• Surgical referral for all symptomatic gallstones (cholecystectomy)
• Emergency surgical review for cholecystitis, cholangitis, gallstone pancreatitis
• ERCP for CBD stones

Asymptomatic gallstones rarely cause problems — <4% become symptomatic per year. After first episode of biliary colic, ~70% have further episodes within 2 years. Laparoscopic cholecystectomy has <0.5% mortality and <5% complication rate. Post-cholecystectomy syndrome (persistent pain) occurs in ~10-15%. Bile duct injury during laparoscopic cholecystectomy occurs in ~0.3-0.5%. Gallstone pancreatitis: recurrence is 20-30% without cholecystectomy.

Gallstone Complication Summary