G

gallbladder A small, muscular pouch on the
underside of the LIVERthat concentrates and stores
BILE. The gallbladder absorbs about 90 percent of
the water in the bile that arrives from the liver,
creating concentrated, potent bile. Fats and pro-
teins in the chyme (partly digested food) the STOM-
ACHsends to the DUODENUMtrigger the duodenum
to release the digestive HORMONEcholecystokinin
(CCK). CCK stimulates the gallbladder to contract,
expelling bile into the duodenum to aid with
digestion. The most common health conditions
that affect the gallbladder are cholelithiasis (gall-
stones), cholecystitis (INFLAMMATION of the gall-
bladder), and biliary dyskinesia (inadequate
contraction of the gallbladder). CANCERof the gall-
bladder occurs though is rare.
For further discussion of the gallbladder within
the context of gastrointestinal structure and func-
tion, please see the overview section “The Gas-
trointestinal System.”
See also CHOLECYSTECTOMY; DIGESTIVE HORMONES;
GALLBLADDER DISEASE.

gallbladder disease Disorders and dysfunctions
of the GALLBLADDER. Gallbladder disease becomes
more common with increasing age. Though med-
ical treatments can help some people with gallblad-
der disease, surgery to remove the gallbladder is the
most common treatment and permanently resolves
symptoms in about 90 percent of people who have
primary gallbladder disease. Tumors and CANCERof
the gallbladder occur, though are very rare.
INFLAMMATIONof the BILE DUCTSand HEPATITISalso can
affect BILE production and gallbladder function.
Gallbladder disease can be acute or chronic.
Biliary dyskinesia Dysfunction of the gallblad-
der prevents it from contracting to eject bile,
reducing or stopping the flow of bile from the gall-

bladder to the DUODENUM (first segment of the

small intestine). Biliary dyskinesia may occur as a

result of injury to the nerves that supply the gall-

bladder, as a consequence of metabolic disorders

affecting LIVERfunction, or for unknown reasons

(most common).

Cholelithiasis Commonly called gallstones,

cholelithiasis develops over years to decades in

most people. Gallstones can range in size from a

few millimeters to several centimeters. There can

be one to a few to dozens. About 80 percent of

gallstones contain mostly cholesterol; bile pig-

ments such as BILIRUBINmake up the remainder.

Many people have gallstones without symptoms.

Gallstones become a health concern when they

lodge in the bile ducts or when they cause irrita-

tion and inflammation of the gallbladder’s

mucosal lining. In a variation of cholelithiasis,

called choledocholithiasis, the gallstones form in

the bile ducts.

Cholecystitis Inflammation or INFECTIONof the

gallbladder most commonly occurs in conjunction

with gallstones that block the flow of bile out of

the gallbladder, though it can develop in biliary

dyskinesia when the bile in the gallbladder stag-

nates. This stagnation irritates and inflames the

lining of the gallbladder. Cholecystitis that occurs

without gallstones is acalculus cholecystitis.

GALLBLADDER DISEASE AND WEIGHT LOSS

These weight-loss efforts increase the risk for

gallbladder disease:

• rapid weight loss (3 pounds a week or greater)


• BARIATRIC SURGERY (gastric banding, stapling,
  bypass)


• weight loss cycling (cycles of loss and regain-
  ing weight, especially large amounts)

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