Bile is a fluid made in the liver. Bile contains various substances
including bile pigments, bile salts, cholesterol and lecithin. Bile is
passed into tiny tubes called bile ducts. The bile ducts join together
(like the branches of a tree) to form the main bile duct. Bile
constantly drips down the bile ducts, into the main bile duct, and then
into the gut.
The
gallbladder lies under the liver on the right side of the upper
abdomen. It is like a pouch which comes off the main bile duct and
fills with bile. It is a 'reservoir' which stores bile. The gallbladder
contracts (squeezes) when we eat. This empties the stored bile back
into the main bile duct. The bile passes along the remainder of the
bile duct into the duodenum (the first part of the gut after the
stomach).
Bile helps to digest food, particularly fatty foods.
What are gallstones?
Gallstones
occur when bile, which is normally fluid, forms stones. Gallstones
commonly contain lumps of cholesterol-like (fatty) material that has
solidified and hardened. Sometimes bile pigments or calcium deposits
form gallstones. Sometimes just a few small stones are formed,
sometimes a great many. Occasionally, just one large stone is formed.
About
1 in 3 women, and 1 in 6 men, form gallstones at some stage in their
life. Gallstones become more common with increasing age. The risk of
forming gallstones increases with pregnancy, obesity, rapid weight
loss, and if you take certain medicines such as the contraceptive pill.
Being vegetarian and drinking a moderate amount of alcohol may reduce
the risk of forming gallstones.
What problems can gallstones cause?
Commonly they cause no problems
Most people
with gallstones do not know they have them. It is common to have stones
in the gallbladder that cause no symptoms. (Because gallstones are
common, they are often found when the abdomen is scanned or X-rayed.
These tests may be done when looking for the cause of abdominal
symptoms. If gallstones are found this does not always mean that they
are the cause of symptoms. They may be, but they are sometimes blamed
for causing symptoms which are due to other causes.)
Possible problems
About 3 in 10 people with gallstones develop symptoms or problems. These include:
-
Biliary colic. This is a severe pain in the upper
abdomen. The pain is usually worst to the right-hand side, just below
the ribs. It is caused by a stone that gets stuck in the cystic duct.
This is the small tube that takes bile from the gallbladder to the bile
duct. The gallbladder then squeezes hard to dislodge the stone, and
this causes pain. The pain eases and goes if the gallstone is pushed
out into the bile duct (and then usually out into the gut), or if it
falls back into the gallbladder. Pain from bilary colic can last
just a few minutes, but more commonly lasts several hours. A severe
pain may only happen once in your lifetime, or it may flare up from
time to time. Sometimes less severe but niggly pains occur now and
then, particularly after a fatty meal when the gallbladder contracts
most.
