There are many
events that may promote cholelithiasis:
• The liver
secretes too much cholesterol into the bile.
• The
gallbladder may not be able to empty normally, so bile becomes
stagnant.
• The cells lining the gallbladder may not be able to efficiently
absorb cholesterol and fat from bile.
• There are high
levels of bilirubin. Bilirubin is a substance normally formed by the
breakdown of hemoglobin in the blood. It is removed from the body in
bile. Some experts believe bilirubin may play an important role in
the formation of cholesterol gallstones.
Pigment Stones.
Pigment stones are composed of calcium bilirubinate, or calcified
bilirubin. Pigment stones can be black or brown.
• Black stones
form in the gallbladder and are the more common type. They represent
20% of all gallstones in the U.S. They are more likely to develop in
people with hemolytic anemia (a relatively rare anemia in which red
blood cells are destroyed) or cirrhosis (scarred liver).
• Brown pigment
stones are more common in Asian populations. They contain more
cholesterol and calcium than black pigment stones and are more
likely to occur in the bile ducts. Infection plays a role in the
development of these stones.
Mixed stones. Mixed stones are a mixture of cholesterol and pigment
stones.
UK, London
Montenegro, Podgorcia
Finland, Helsinki
China, Beijing
Belarus, Minsk
Cessnock, Australia
Russia, Moscow
Botswana, Gaborone
Brunei, Darussalam Bandar Seri Begawan
Stockton, California, USA