42. Cholelithiasis, choledocholithiasis, biliary colic

Covers gallstone formation in the gallbladder and in the common bile duct, and the episodic pain of biliary colic. It sets out the two main stone types with their associations, the multifactorial causes and risk factors, then pathogenesis, symptoms and examination and laboratory findings. Imaging is covered with the test regarded as the gold standard for each condition, followed by treatment options and the complications such as cholangitis and gallstone pancreatitis. A mnemonic for risk factors is included.

Inside: 8 sections · 2 labelled pictures · 15 flashcards · 2 min

Topic 40 of 58 in the MU Sofia syllabus for Internal Medicine (Theory) (Medicine, Year 3). The free AceMed note covers it in 8 sections, about 318 words (2 min of reading), with 15 flashcards.

Definition:

Cholelithiasis: Formation of gallstones in the gallbladder.
Choledocholithiasis: Presence of gallstones in the common bile duct (CBD).
Biliary colic: Sudden episodic pain due to temporary obstruction of the cystic duct by a gallstone.

Types of Stones:

Cholesterol stones: Yellow, radiolucent (most common in Western countries); often solitary or few.
Pigment stones:
Black: Associated with hemolysis (e.g. chronic hemolytic anemia).
Brown: Associated with infection or biliary stasis.

Etiology / Risk Factors:

Multifactorial origin, mainly involving:
Supersaturation of bile with cholesterol (↓ solubility).
Impaired gallbladder motility (↓ contraction, e.g. pregnancy, fasting).
Stasis and mucin hypersecretion (acts as a nucleating agent).
Risk factors:
Female, Fat, Forty, Fertile, Fair
Estrogen (pregnancy, OCPs), obesity, rapid weight loss, diabetes
Hemolytic anemia (bilirubin stones)
Family history, liver disease

Pathogenesis:

Bile supersaturated with cholesterol → crystallization → stone formation
Decreased gallbladder motility or biliary stasis → retention of crystals → growth of stones

Symptoms:

Often asymptomatic (especially with small stones)
Biliary colic:
Sudden, severe RUQ or epigastric pain lasting 1–6 hours, often after fatty meals
May radiate to the right shoulder or back
Nausea, vomiting, bloating, indigestion
If stone obstructs CBD → possible jaundice, cholangitis, or pancreatitis