Editing Gallstone disease (section)

== '''Pathophysiology''' ==

=== Cholesterol stones ===

** Bile salts and lecithin render cholesterol soluble in bile by acting as detergents
** When cholesterol concentration exceeds the solubility capacity of bile, it nucleates into solid cholesterol monohydrate crystals
** Cholesterol precipitates into sludge, then stones as the precipitation progresses
** Main factors provoking cholesterol gallstone formation:
*** Supersaturation of secreted bile from the liver
**** Either cholesterol and lipids for cholesterol stones, or haemoglobin processing products for pigment stones
*** Concentration of bile in the GB
**** Absorption of water and sodium
*** GB dysmotility
**** Allows more time for solutes to precipitate in the GB
**** Prolonged fasting, TPN, after vagotomy, somatostatin analogues
*** Accelerated crystal enucleation
**** Process accelerated by pro-nucleating agents - glycoproteins and immunoglobulins

=== Pigment stones ===

** Complex mixtures of insoluble calcium salts of unconjugated bilirubin and inorganic calcium salts
** High levels of unconjugated or conjugated bilirubin can predispose
** Infection with certain organisms can favour stone formation - usually brown stones

=== Small's triangle of solubility: ===