Cholelithiasis

Overview – Cholelithiasis

Cholelithiasis refers to the presence of gallstones in the gallbladder and is a common gastrointestinal condition. It may present with biliary colic—sudden, right upper quadrant pain following fatty meals—or remain entirely asymptomatic. While often benign, gallstones can lead to serious complications such as cholecystitis, cholangitis, or pancreatitis. Understanding the underlying pathophysiology and morphology is key for medical management and surgical decision-making.

Definition

Cholelithiasis is the formation of calculi (gallstones) within the gallbladder or biliary tree. These stones vary in composition, shape, and clinical implications.

Aetiology

• Mixed stones – ~80%
  • Combination of cholesterol, calcium, bile pigments, and blood components
• Pigment stones (pure) – ~20%
  • Mainly bilirubin-derived
• Cholesterol-only stones – Rare

Risk Factors

Cholesterol Stones:

• Western demographic
• Female sex
• Pregnancy
• Oral contraceptives
• Obesity, rapid weight loss
• High-fat diets, bile acid metabolism disorders
• Gallbladder stasis
• Hyperlipidemia syndromes

Pigment Stones:

• Asian populations
• Haemolytic anaemias (e.g., sickle cell)
• Chronic infections and inflammation
• Biliary infections
• Ileal disease or resection (e.g., Crohn’s)
• Chronic pancreatitis
• 80% idiopathic
• Highly prevalent in American Pima populations

Pathogenesis

1. Supersaturation of bile with cholesterol or bilirubin
2. Microprecipitation of calcium salts
3. Biliary stasis → mucus traps crystals → aggregation
4. Progressive stone growth over time

Morphology

• Mixed stones:
  • Multiple, faceted, yellow-grey, 20% radio-opaque
• Pigment stones:
  • Dark brown/black, friable, soft, ~50% radio-opaque
• Cholesterol-only stones:
  • Yellow, spiky, rare

Clinical Features

• 80% asymptomatic
• 20% symptomatic:
  • Biliary colic:
    • Severe, colicky upper abdominal pain radiating to the right shoulder
    • Often triggered by fatty meals
  • Fat intolerance
  • Pale, clay-coloured stools (due to lack of bile pigments)

Investigations

• ↑Conjugated bilirubin (suggests extrahepatic obstruction)
• ↑Alkaline phosphatase (cholestatic pattern)
• Abdominal ultrasound – first-line for visualising gallstones

Management

• Initial conservative management:
  • Nil by mouth (bowel rest)
  • IV fluids for hydration
  • Analgesia
  • IV antibiotics (if infection suspected)
• Definitive:
  • Elective cholecystectomy if symptomatic or recurrent attacks

Complications

• Acute or chronic cholecystitis
• Cholangitis
• Pancreatitis
• Cholangiocarcinoma (rare, long-term risk in chronic cholelithiasis)

Summary – Cholelithiasis

Cholelithiasis is the formation of gallstones, usually cholesterol-based, and may present with classic biliary colic or remain asymptomatic. Management involves supportive therapy and often surgical removal if symptoms or complications arise. For related hepatobiliary topics, visit our Gastrointestinal Overview page.