The doctor can diagnose hemorrhoids via phys-
ical examination of the anal area, including DIGITAL
RECTAL EXAMINATION (DRE) or anoscopy, when
symptoms are mild. Treatment attempts to shrink
and soothe the irritated tissues. Topical prepara-
tions containing an anesthetic agent and hydro-
cortisone can provide prompt, short-term relief. A
SITZ BATH, or simply soaking in the bathtub, relaxes
the anal sphincter enough to calm the spasms that
prolapsed or thrombosed (clotted) hemorrhoids
cause. Dietary changes (such as increased fiber
and fluids) combined with frequent physical activ-
ity (such as walking) help to reduce constipation,
which relieves straining and pressure on the
anorectal area. The doctor can ligate (band off),
cauterize, freeze, or excise (cut out) hemorrhoids
that fail to respond to conservative treatment
approaches. In the vast majority of people, appro-
priate treatment and lifestyle modifications end
symptoms.
See also ANAL FISSURE; ENDOSCOPY.
hepatic abscess A pocket of INFECTION that
develops within the LIVER, also called liver ABSCESS.
Though not common, hepatic abscesses can
develop as a complication of GALLBLADDER DISEASE
in which infection spreads through the BILE DUCTS
to the liver. Symptoms include ABDOMINAL PAIN
(often focused in the upper left quadrant), tender-
ness and rigidity, and FEVER. A person with a
hepatic abscess often appears very ill. Abdominal
ULTRASOUND, COMPUTED TOMOGRAPHY(CT) SCAN, and
MAGNETIC RESONANCE IMAGING(MRI) are among the
diagnostic procedures that help detect hepatic
abscess. Treatment is percutaneous aspiration
(inserting a needle through the SKINand into the
abscess) or laparoscopic surgery to drain the col-
lected pus, with intensive antibiotic therapy to
eradicate the infection. An untreated hepatic
abscess can quickly become life-threatening, as
the liver’s rich blood supply can carry the patho-
genic bacteria throughout the body.
See also ANTIBIOTIC MEDICATIONS; MINIMALLY INVA-
SIVE SURGERY; SEPTICEMIA.
hepatic cyst A noncancerous growth, often
fluid-filled, that develops in the LIVER. Most simple
hepatic cysts cause no symptoms; they become
apparent during diagnostic procedures, such as
abdominal ULTRASOUND, done for other reasons.
When there are no symptoms, no treatment is
necessary beyond regular monitoring (watchful
waiting). A hydatid cyst contains the larvae of the
PARASITEEchinococcus granulosus,acquired through
contact with animal feces that contain the para-
site’s eggs, which migrate to the liver. A hydatid
cyst grows slowly though can become large
enough to hold a liter or more of fluid. Even
when hydatid cysts show no symptoms, doctors
remove them because they can cause life-threat-
ening complications such as PERITONITIS or SEP-
TICEMIAif they rupture. Removal of a hepatic cyst
is nearly always a laparoscopic surgery.
See also MINIMALLY INVASIVE SURGERY; PERCUTA-
NEOUS LIVER BIOPSY.hepatitis INFLAMMATION of the LIVER. There are
numerous kinds and causes of hepatitis. Most
hepatitis results from specific viruses that cause
infections of the liver,ALCOHOLabuse, and hepato-
toxic drugs. Hepatitis is the leading cause of LIVER
FAILURE, and reason for LIVER TRANSPLANTATION, in
the United States.
Infectious (viral) hepatitis The viruses that
cause viral hepatitis belong to several virus fami-
lies: the picornavirus family, which causes hepati-
tis A; the hepacivirus family, which causes
hepatitis B; and the flavirus family, which causes
hepatitis C.
Though these viruses are among the smallest
researchers have yet detected, they cause a wide
range of illnesses from COLDSto viral MENINGITISto
POLIO. Researchers refer to those that specifically
target the liver as hepatotropic and label them
alphabetically in the sequence of their discovery.
Each individual VIRUS has unique characteristics
that cause a particular pattern of disease.
Researchers classify viral hepatitis according to the
viral variant responsible for the disease response.
Five viruses identified as hepatotropic (“liver
loving”) cause 95 percent of the infectious hepati-
tis diagnosed in the United States: hepatitis A
(HAV), hepatitis B (HBV), hepatitis C (HCV), hep-
atitis D (HDV), and hepatitis E (HEV). Hepatitis A
and hepatitis E cause acute infection only and
rarely cause permanent liver damage, though hep-
atitis A infection can cause serious illness and
fatality. Hepatitis A accounts for more than 6054 The Gastrointestinal System