Cholelithiasis

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management

Definition

Cholelithiasis refers to the presence of gallstones in the gallbladder. Gallstones are solid deposits primarily composed of cholesterol, bilirubin, or calcium salts, which can cause biliary obstruction or inflammation.

Aetiology

Gallstones form due to an imbalance in the composition of bile, which can lead to crystallisation and stone formation. Types of gallstones include:

  • Cholesterol stones: most common, associated with obesity, pregnancy, and high-fat diets.
  • Pigment stones: contain bilirubin, commonly seen in haemolysis and chronic liver disease.
  • Mixed stones: contain cholesterol, bile salts, and calcium, occurring in most cases.

Pathophysiology

  • Gallstones form when bile becomes supersaturated with cholesterol, leading to crystallisation.
  • Sluggish bile flow promotes stone formation, especially in fasting or rapid weight loss.
  • Stones may remain asymptomatic or obstruct the cystic or common bile duct, leading to complications.

Risk factors

  • Age: more common in individuals over 40 years.
  • Sex: more prevalent in females due to oestrogen's effect on bile composition.
  • Obesity and metabolic syndrome.
  • Rapid weight loss or fasting.
  • Pregnancy.
  • Haemolytic conditions: such as sickle cell disease (risk of pigment stones).
  • Chronic liver disease.

Signs and symptoms

Asymptomatic Gallstones:

  • Most cases are incidental findings on imaging.
  • No treatment is needed if asymptomatic.

Symptomatic Cholelithiasis:

  • Biliary colic: intermittent right upper quadrant (RUQ) pain, often triggered by fatty meals.
  • Nausea and bloating.
  • Pain radiating to the right shoulder or back.

Complications:

  • Cholecystitis: persistent RUQ pain, fever, Murphy’s sign positive.
  • Choledocholithiasis: gallstones in the common bile duct, leading to jaundice and dark urine.
  • Gallstone pancreatitis: severe epigastric pain with raised amylase.

Investigations

  • Blood tests:
    • Liver function tests: Raised ALP and bilirubin if bile duct obstruction.
    • CRP and WCC: raised in cholecystitis.
    • Serum amylase: raised in gallstone pancreatitis.
  • Imaging:
    • Abdominal ultrasound (first-line): detects gallstones and thickened gallbladder wall.
    • MRCP: if bile duct stones are suspected.
    • CT scan: less sensitive for gallstones but used in complications.

Management

1. Asymptomatic Gallstones:

  • No treatment required unless complications develop.
  • Lifestyle modifications (weight management, low-fat diet).

2. Symptomatic Gallstones:

  • Analgesia: NSAIDs or paracetamol for pain relief.
  • Low-fat diet: to reduce symptoms.
  • Elective laparoscopic cholecystectomy: recommended for recurrent biliary colic.

3. Complicated Cholelithiasis:

  • Acute cholecystitis: IV antibiotics (co-amoxiclav), fluids, and early laparoscopic cholecystectomy.
  • Choledocholithiasis: Endoscopic retrograde cholangiopancreatography (ERCP) with stone removal.
  • Gallstone pancreatitis: supportive care and cholecystectomy after recovery.
GastroenterologymypanotesCholelithiasis