Webster's New World Medical Dictionary

cold sore
A small sore located on the face or in
the mouth that causes pain, burning, or itching
before bursting and crusting over. Common loca-
tions for cold sores are the lips, chin, cheeks, and
nostrils. Cold sores more rarely appear on the gums
and the roof of the mouth. Cold sores are caused by
herpes simplex type 1 virus, which lies dormant in
the body and is reawakened by factors such as
stress, sunburn, or fever from a wide range of infec-
tious diseases, including colds. Sunscreen (SPF 15
or higher) on the lips prevents recurrences of her-
pes due to sunburn. The virus is highly contagious
when fever blisters are present. It is spread by phys-
ical contact, such as kissing. Also known as labial
herpes, febrile herpes, and fever blister.
colectomy
An operation to remove all or part of
the colon (large intestine). In a partial colectomy,
the surgeon removes only part of the colon. The
bowel is then reconnected or an opening of the
bowel (ostomy) is created on the abdominal wall to
allow the contents of the bowel to exit from the
body. Colectomy may be needed for treatment of
diverticulitis, benign polyps of the colon, and can-
cer of the colon.
colic
A cause of crampy abdominal pain in early
infancy. Colic is a common condition, occurring in
about 1 in 10 babies. An infant with colic is irrita-
ble, cries, and often has a rigid abdomen and draws
up its legs. Overfeeding, undiluted juices, food aller-
gies, and stress can aggravate colic. Colic usually
lasts from early infancy to the third or fourth month
of age. Treatment can include dietary changes, care-
fully measured feedings, and extra burping. Parents
should not assume that new abdominal pain and
loud crying in their baby are colic. It is important
for the baby to be seen by a physician to rule out
more serious conditions.
colitis
Inflammation of the colon (large intes-
tine). There are many forms of colitis, including
amebic, Crohn’s, infectious, pseudomembranous,
spastic, and ulcerative.
colitis, amebic
Inflammation of the intestine,
with ulcers in the colon, due to infection with an
ameba called Entamoeba histolytica. This parasite
can be transmitted to humans via contaminated
water and food. Symptoms, which include diarrhea,
indigestion, nausea, and weight loss, can begin
shortly after infection, or the ameba may live in the
gastrointestinal tract for months or years before
symptoms erupt. Amebic colitis can be treated with
medication, including emetine and antibiotics. See
also 
amebic dysentery; amebiasis.