What Are Gallstones?
Gallstones form when liquid called bile is stored in the gallbladder hardens
into pieces of stone-like material. The bile, is used to help the body
digest fats. Bile is made in the liver, then stored in the gallbladder
until the body needs to digest fat. At that time, the gallbladder contracts
and pushes the bile into a tube—called a duct—that carries it to the small
intestine, where it helps with digestion.
Bile is a brown liquid which contains bile salts, cholesterol, bilirubin,
and lecithin. About three cups are produced by the liver every day. Some
substances in bile, including bile salts and lecithin, act like detergents
to break up fat so that it can be easily digested. Others, like bilirubin,
are waste products. Bilirubin is a dark brown substance which gives a
brown color to both bile and to stool
If the liquid bile contains too much cholesterol, bile
salts, or bilirubin, it can harden into stones. The two types of gallstones
are cholesterol stones and pigment stones. Cholesterol stones are usually
yellow-green and are made primarily of hardened cholesterol. They account
for about 80 percent of gallstones. Pigment stones are small, dark stones
made of bilirubin. Some gallstones are tiny ; as small as a grain of sand;
others reach the size of a golf ball. Some people have only one stone;
others develop hundreds.
The gallbladder and the ducts that carry bile and other digestive
enzymes from the liver, gallbladder, and pancreas to the small intestine
are called the biliary system.
The gallbladder and the ducts that carry bile and other
digestive enzymes from the liver, gallbladder, and pancreas to the small
intestine are called the biliary system. Gallstones can block the normal
flow of bile if they lodge in any of the ducts that carry bile from the
liver to the small intestine. That includes the hepatic ducts, which carry
bile out of the liver; the cystic duct, which takes bile to and from the
gallbladder; and the common bile duct, which takes bile from the cystic
and hepatic ducts to the small intestine. Bile trapped in these ducts
can cause inflammation in the gallbladder, the ducts, or, rarely, the
liver. Other ducts open into the common bile duct, including the pancreatic
duct, which carries digestive enzymes out of the pancreas.
Symptoms: Severe, steady (not fluctuating) pain in the upper right abdomen,
which may spread to include the chest, back (between the shoulder blades)
and shoulders; this pain may last as little as 15 minutes or as long as
several hours; you may feel a repeat episode of pain a few hours later,
or it may take weeks, months or even years for another attack to occur.
Nausea Vomiting Sweating Jaundice (yellowing of the skin and whites of
the eyes). Many people have "silent" gallstones and may experience no
symptoms for months or years or even a lifetime.
Biliary colic is an extremely severe pain in the upper right-hand part
of the abdomen. The pain, which comes and goes, is often accompanied by
sweating and vomiting. It is the result of a spasm of the gall bladder
or of obstruction of the bile ducts, either of which is caused by one
or more gallstones.
If a gallstone blocks the opening to that duct, digestive enzymes
can become trapped in the pancreas and cause an extremely painful inflammation
called pancreatitis. If any of these ducts remain
blocked for a significant period of time, severe—possibly fatal—damage
can occur, affecting the gallbladder, liver, or pancreas. Warning
signs of a serious problem are fever, jaundice, and persistent pain.
In rare cases, a gallstone may erode through the wall of the gallbladder,
enter the intestine and migrate to the wall of the ileocecal valve, the
point at which the small and large intestines meet. This is called a gallstone
ileus, and it may result in bowel obstruction, another
very serious and potentially life-threatening event requiring emergency
What Causes Gallstones? Cholesterol Stones Scientists believe cholesterol
stones form when bile contains too much cholesterol, too much bilirubin,
or not enough bile salts, or when the gallbladder does not empty as it
should for some other reason. Pigment Stones The cause of pigment stones
is uncertain. They tend to develop in people who have cirrhosis, biliary
tract infections, and hereditary blood disorders such as sickle cell anemia.
Other Factors It is believed that the mere presence of gallstones may
cause more gallstones to develop. However, other factors that contribute
to gallstones have been identified, especially for cholesterol stones.
Obesity. Obesity is a major risk factor for gallstones, especially in
women. A large clinical study showed that being even moderately overweight
increases one's risk for developing
moderately overweight increases one's risk for developing gallstones.
The most likely reason is that obesity tends to reduce the amount of bile
salts in bile, resulting in more cholesterol. Obesity also decreases gallbladder
emptying. Estrogen. Excess estrogen from pregnancy, hormone replacement
therapy, or birth control pills appears to increase cholesterol levels
in bile and decrease gallbladder movement, both of which can lead to gallstones.
Ethnicity. Native Americans have a genetic predisposition to secrete high
levels of cholesterol in bile. In fact, they have the highest rates of
gallstones in the United States. A majority of Native American men have
gallstones by age 60. Among the Pima Indians of Arizona, 70 percent of
women have gallstones by age 30. Mexican-American men and women of all
ages also have high rates of gallstones. Gender. Women between 20 and
60 years of age are twice as likely to develop gallstones as men. Age.
People over age 60 are more likely to develop gallstones than younger
people. Cholesterol-lowering drugs. Drugs that lower cholesterol levels
in blood actually increase the amount of cholesterol secreted in bile.
This in turn can increase the risk of gallstones. Diabetes. People with
diabetes generally have high levels of fatty acids called triglycerides.
These fatty acids increase the risk of gallstones. Rapid weight loss.
As the body metabolizes fat during rapid weight loss, it causes the liver
to secrete extra cholesterol into bile, which can cause gallstones. Fasting.
Fasting decreases gallbladder movement, causing the bile to become overconcentrated
with cholesterol, which can lead to gallstones. Who Is at Risk for Gallstones?
Women. People over age 60. Native Americans. Mexican-Americans. Overweight
men and women. People who fast or lose a lot of weight quickly. Pregnant
women, women on hormone therapy, and women who use birth control pills.
What are the Symptoms? Symptoms of gallstones are often called a gallstone
"attack" because they occur suddenly. A typical attack can cause Steady,
severe pain in the upper abdomen that increases rapidly and lasts from
30 minutes to several hours. Pain in the back between the shoulder blades.
Pain under the right shoulder. Nausea or vomiting. Gallstone attacks often
follow fatty meals, and they may occur during the night. Other gallstone
symptoms include Abdominal bloating. Recurring intolerance of fatty foods.
Colic. Belching. Gas. Indigestion. People who also have the following
symptoms should see a doctor right away: Sweating. Chills. Low-grade fever.
Yellowish color of the skin or whites of the eyes. Clay-colored stools.
Many people with gallstones have no symptoms. These patients are said
to be asymptomatic, and these stones are called "silent stones." They
do not interfere in gallbladder, liver, or pancreas function and do not
How Are Gallstones Diagnosed? millions of people, gallstones are "silent,"
never causing symptoms. Many people may not be aware that they have gallstones;
gallstones are often discovered incidentally, during diagnostic tests
for other conditions. But when gallstones are suspected to be the cause
of symptoms, the doctor is likely to do an ultrasound exam.
Ultrasound uses sound waves to create images of organs.
Sound waves are sent toward the gallbladder through a handheld device
that a Radiologist glides over the abdomen. The sound waves bounce off
the gallbladder, liver, and other organs, and their echoes make electrical
impulses that create a picture of the organ on a video monitor. If stones
are present, the sound waves will bounce off them, too, showing their
location. Other tests used in diagnosis include Cholecystogram or cholescintigraphy.
The patient is injected with a special iodine dye, and x-rays are taken
of the gallbladder over a period of time. (Some people swallow iodine
pills the night before the x-ray.) The test shows the movement of the
gallbladder and any obstruction of the cystic duct.
Endoscopic retrograde cholangiopancreatography (ERCP). The patient swallows
an endoscope—a long, flexible, lighted tube connected to a computer and
TV monitor. The Gastroenterologist guides the endoscope through the stomach
and into the small intestine. The doctor then injects a special dye that
temporarily stains the ducts in the biliary system. ERCP is used to locate
stones in the ducts. Blood tests. Blood tests may be used to look for
signs of infection, obstruction, pancreatitis, or jaundice. Gallstone
symptoms are similar to those of heart attack, appendicitis, ulcers, irritable
bowel syndrome, hiatal hernia, pancreatitis, and hepatitis. So accurate
diagnosis is important. What is the Treatment? Surgery Surgery to remove
the gallbladder is the most common way to treat symptomatic gallstones.
(Asymptomatic gallstones usually do not need treatment.) Each year more
than 500,000 Americans have gallbladder surgery. The surgery is called
cholecystectomy. The standard surgery is called laparoscopic cholecystectomy.
For this operation, the surgeon makes several tiny incisions in the abdomen
and inserts surgical instruments and a miniature video camera into the
abdomen. The camera sends a magnified image from inside the body to a
video monitor, giving the surgeon a closeup view of the organs and tissues.
While watching the monitor, the surgeon uses the instruments to carefully
separate the gallbladder from the liver, ducts, and other structures.
Then the cystic duct is cut and the gallbladder removed through one of
the small incisions.
Because the abdominal muscles are not cut during laparoscopic surgery,
patients have less pain and fewer complications than they would have had
after surgery using a large incision across the abdomen. Recovery usually
involves only one night in the hospital, followed by several days of restricted
activity at home. If the surgeon discovers any obstacles to the laparoscopic
procedure, such as infection or scarring from other operations, the operating
team may have to switch to open surgery. In some cases the obstacles are
known before surgery, and an open surgery is planned. It is called "open"
surgery because the surgeon has to make a 5- to 8-inch incision in the
abdomen to remove the gallbladder. This is a major surgery and may require
about a 2- to 7-day stay in the hospital and several more weeks at home
to recover. Open surgery is required in about 5 percent of gallbladder
operations. The most common complication in gallbladder surgery is injury
to the bile ducts. An injured common bile duct can leak bile and cause
a painful and potentially dangerous infection. Mild injuries can sometimes
be treated nonsurgically. Major injury, however, is more serious and requires
additional surgery. If gallstones are in the bile ducts, the surgeon may
use ERCP in removing them before or during the gallbladder surgery. Once
the endoscope is in the small intestine, the surgeon locates the affected
bile duct. An instrument on the endoscope is used to cut the duct, and
the stone is captured in a tiny basket and removed with the endoscope.
This two-step procedure is called ERCP with endoscopic sphincterotomy.
Occasionally, a person who has had a cholecystectomy is diagnosed with
a gallstone in the bile ducts weeks, months, or even years after the surgery.
The two-step ERCP procedure is usually successful in removing the stone.
Nonsurgical Treatment Nonsurgical approaches are used only in special
situations—such as when a patient's condition prevents using an anesthetic—and
only for cholesterol stones. Stones recur after nonsurgical treatment
about half the time. Oral dissolution therapy. Drugs made from bile acid
are used to dissolve the stones. The drugs, ursodiol (Actigall) and chenodiol
(Chenix), work best for small cholesterol stones. Months or years of treatment
may be necessary before all the stones dissolve. Both drugs cause mild
diarrhea, and chenodiol may temporarily raise levels of blood cholesterol
and the liver enzyme transaminase. Contact dissolution therapy. This experimental
procedure involves injecting a drug directly into the gallbladder to dissolve
stones. The drug—methyl tert butyl—can dissolve some stones in 1 to 3
days, but it must be used very carefully because it is a flammable anesthetic
that can be toxic. The procedure is being tested in patients with symptomatic,
noncalcified cholesterol stones. Extracorporeal shockwave lithotripsy
(ESWL). This treatment uses shock waves to break up stones into tiny pieces
that can pass through the bile ducts without causing blockages. Attacks
of biliary colic (intense pain) are common after treatment, and ESWL's
success rate is not very high. Remaining stones can sometimes be dissolved
with medication. Don't People Need Their Gallbladders? Fortunately, the
gallbladder is an organ that people can live without. Losing it won't
even require a change in diet. Once the gallbladder is removed, bile flows
out of the liver through the hepatic ducts into the common bile duct and
goes directly into the small intestine, instead of being stored in the
gallbladder. However, because the bile isn't stored in the gallbladder,
it flows into the small intestine more frequently, causing diarrhea in
some people. Also, some studies suggest that removing the gallbladder
may cause higher blood cholesterol levels, so occasional cholesterol tests
may be necessary.
Points To Remember
Gallstones form when substances in the bile harden.
Gallstones are common among women, Native Americans, Mexican-Americans,
and people who are overweight.
Gallstone attacks often occur after eating a fatty meal. Symptoms can
mimic those of other problems, including heart attack, so accurate diagnosis
Gallstones can cause serious problems if they become trapped in the bile
Laparoscopic surgery to remove the gallbladder is the most common treatment.
|Cholecystitis is defined as inflammation of the gallbladder that
occurs most commonly because of obstruction of the cystic duct from
cholelithiasis. Ninety percent of cases involve stones in the cystic
duct (ie, calculous cholecystitis), with the other 10% representing
acalculous cholecystitis. Although bile cultures are positive for
bacteria in 50-75% of cases, bacterial proliferation may be a result
of cholecystitis and not the precipitating factor. Risk factors for
cholecystitis mirror those for cholelithiasis and include increasing
age, female sex, certain ethnic groups, obesity or rapid weight loss,
drugs, and pregnancy.
|Acalculous cholecystitis is related to conditions associated with
biliary stasis, including debilitation, major surgery, severe trauma,
sepsis, long-term total parenteral nutrition (TPN), and prolonged
fasting. Other causes of acalculous cholecystitis include cardiac
events; sickle cell disease; Salmonella infections; diabetes mellitus;
and cytomegalovirus, cryptosporidiosis, or microsporidiosis infections
in patients with AIDS.
The most common presenting symptom of acute cholecystitis is upper
abdominal pain, often radiating to the tip of the right scapula.
Most patients with acute cholecystitis describe a history of biliary
pain. Some patients may have documented gallstones. Acalculous biliary
colic also occurs, most commonly in young–to–middle-aged
females. The presentation is almost identical to calculous biliary
colic with the exception of reference range laboratory values and
no findings of cholelithiasis on ultrasound.
Frequently, the pain begins in the epigastric region and then localizes
to the right upper quadrant (RUQ). Although the pain may initially
be described as colicky, it becomes constant in virtually all cases.
Signs of peritoneal irritation may be present, and, in some patients,
the pain may radiate to the right shoulder or scapula.
Nausea and vomiting are generally present, and patients may report
In elderly patients, pain and fever may be absent, and localized
tenderness may be the only presenting sign. Patients with acalculous
cholecystitis may present similarly to patients with calculous cholecystitis,
but acalculous cholecystitis frequently occurs suddenly in severely
ill patients without a prior history of biliary colic. Often, patients
with acalculous cholecystitis may present with fever and sepsis
alone, without history or physical examination findings consistent
with acute cholecystitis.
Cholecystitis is differentiated from biliary colic by the persistence
of constant severe pain for more than 6 hours
|Physical examination may reveal fever, tachycardia, and tenderness
in the RUQ or epigastric region, often with guarding or rebound.
A palpable gallbladder or fullness of the RUQ is present in 30-40%
Jaundice may be noted in approximately 15% of patients.
The absence of physical findings does not rule out the diagnosis of
cholecystitis. Many patients present with diffuse epigastric pain
without localization to the RUQ. Patients with chronic cholecystitis
frequently do not have a palpable RUQ mass secondary to fibrosis involving
Elderly patients and patients with diabetes frequently have atypical
presentations, including absence of fever and localized tenderness
with only vague symptoms.
Murphy sign, which is specific but not sensitive for cholecystitis,
is described as tenderness and an inspiratory pause elicited during
palpation of the RUQ.
|Biliary colic represents one of the causes of epigastric pain and
is the most common presentation of symptomatic gallstone disease (cholelithiasis/choledocholithiasis).
Because this is a symptom, numerous other disease processes may result
in pain that is similar to biliary colic. These disease processes
should be considered during the evaluation of patients being considered
to have biliary colic. The pain of biliary colic is listed inaccurately
as a colic because this term implies a paroxysmal pain that is waxing
and waning in nature. This often is not the case.
Careful history and examination are cornerstones to making an accurate
clinical diagnosis, essentially because of the high incidence of
gallstones in the population and because most gallstones are asymptomatic.
The potential disastrous implications of a misdiagnosis as biliary
colic instead of alternative diagnoses that may present with epigastric
pain (eg, atypical myocardial ischemia) cannot be overemphasized.
Patients also can be particularly unhappy and frustrated when their
pain is not resolved following cholecystectomy. The differential
diagnosis section lists other important medical conditions one should
consider in patients who present with possible biliary colic (see
History should elicit the nature, intensity, location, duration,
onset, cessation, associated factors, aggravating factors, relieving
factors, radiation, and frequency (NILDOCARRF) of the pain (see
History). At the same time, one should evaluate risk factors for
stone formation while addressing potentially confounding factors
such as medical comorbidities (eg, cardiovascular disease).
This visceral pain is believed to result from impaction of a gallstone
in the cystic duct and/or ampulla of Vater, causing distension of
the gallbladder and/or biliary tract; this activates visceral afferent
sensory neurons. The pain commonly is localized poorly and referred
midline to representative dermatomes T8/9 (mid epigastrium, right
upper quadrant). Localized pain generally represents a complication
of cholelithiasis or choledocholithiasis (eg, cholecystitis, cholangitis,
Biliary colic is the presenting symptom in 80% of patients with
gallstone disease who seek medical care; however, only 10-20% of
all individuals with gallstones experience severe gallstone pain.
The risk of developing biliary pain or stone-related complications
in asymptomatic patients is low, at 1-2% per year. For this reason,
clinical practice favors treatment of only symptomatic disease,
with the exception of a few unique circumstances. Two thirds of
patients presenting with their first attack of biliary colic have
recurrent pain within 2 years.
Pathophysiology: A gallstone produces visceral pain by obstructing
the cystic duct or ampulla of Vater, resulting in distention of
the gallbladder or biliary tree. Pain is relieved when the gallstone
migrates back into the gallbladder, passes through the ampulla,
or falls back into the common bile duct (CBD). The pain of biliary
colic may accompany sphincter of Oddi spasm.