COLON, DISORDERS OF
C
bowel movements (either constipation
or diarrhoea), blood mixed in with the
faeces, and pain in the lower abdomen.
Sometimes,
however,
there
are
no
symptoms until the tumour has grown
large enough to cause an obstruction
in the intestine (see
intestine, obstruction
of) or perforate it (see
perforation
) .
DIAGNOSIS AND TREATMENT
Successful treatment of cancer of the
colon depends, crucially, on an early
diagnosis. Screening may be carried out
to detect early signs. This procedure
includes a test to detect blood hidden
in the faeces
(see
faecal occult blood
test
) .
If the test is positive, doctors may
perform
sigmoidoscopy
and
colonoscopy
to view the inside of the colon. A
biopsy
may be performed at the same time.
In most cases, a partial
colectomy
is
carried out. In this procedure, the dis-
eased part of the colon is removed,
together with a surrounding area of
healthy tissue, then the cut ends of the
colon are rejoined. Surgery may be
combined with
radiotherapy
or possibly
with
chemotherapy
.
The chance of sur-
vival depends on how far the tumour
has spread, but colon cancer in its early
stages can be cured.
colon, disorders of
See
intestine, disorders of.
colon, irritable
See
irritable bowel syndrome
.
colonization
The multiplication of foreign organ-
isms, such as
bacteria
,
in a host body.
(This process is not necessarily harm-
ful.) The term “colonization” is also
used to refer to the development of
cancer
cells in an area to w hich they
have spread that is separate from the
prim ary tumour.
colonoscopy
The viewing of the inside of the
colon
using a flexible endoscope (fibre-optic
instrument) known as a colonoscope,
w hich is introduced through the
anus
and guided along the colon. Colonos-
copy is used to investigate symptoms
such as bleeding from the anus and to
detect physical abnormalities such as
inflammation (see
colitis
) ,
growths (see
polyps
) ,
and
cancer
.
Instruments may be
passed through the colonoscope to take
biopsy
specimens
or remove polyps.
(See also
endoscopy
. )
colon, spastic
See
irritable bowel syndrome
.
Colorado tick fever
A viral illness transmitted by the bites
of infected
ticks.
It
occurs
in
the
mountain areas of the western United
States, usually in early summer. Symp-
toms appear
3 - 6
days after a tick bite;
they include flulike chills and fever,
severe headache, nausea, and some-
times a red, raised rash. The illness
usually lasts for a few days, subsides,
then returns for a further few days. The
virus
can,
how-ever,
remain in the
blood for several months.
Treatment involves removal of the
tick as soon as possible and taking
anal-
gesic drugs
(painkillers)
if necessary.
Tick bites can be prevented by wearing
clothing that covers the arms and legs
and tucking trouser legs into socks.
(See also
ticks and disease
. )
colorectal cancer
A general term referring to cancer of
the colon (see
colon, cancer of
)
and/or
of the rectum (see
rectum, cancer of
) .
colostomy
An operation in w hich part of the
colon
is brought to the surface of the skin
through an incision in the abdominal
wall. The exposed part is formed into a
stoma
,
an artificial opening through
w hich
faeces
are discharged into a bag
attached to the skin. A colostomy may
be either temporary or permanent.
A temporary colostomy may be per-
formed at the same time as a partial
colectomy
(removal
of part
of
the
colon) to allow the remainder of the
colon to heal without faeces passing
through and contaminating it. The col-
ostomy is closed when the rejoined
colon has healed. A permanent colosto-
my is needed if the rectum or anus has
been removed (for example, to treat
colon cancer) and norm al defaecation
is therefore impossible.
colostrum
A thick, yellowish fluid that is pro-
duced by the breasts during the first
few days after childbirth, before being
replaced
by
breast
milk.
Colostrum
contains less fat and sugar, but more
minerals and protein, than breast milk.
It also has a high content of
lymphocytes
(white
blood
cells)
and
immuno-
globulins
,
w hich help to protect the
baby against infections.
PROCEDURE FOR COLOSTOMY
An incision is made in the abdominal
wall and part of the colon is pulled
through. In a temporary colostomy, a
small loop is exposed, and an opening
is made in it large enough for faeces to
pass through. If the rectum and anus
have been removed, the cut end of the
colon is brought to the skin surface.
The edges of the opening or severed
end are stitched to the skin at the
edges of the abdominal incision to
create a stoma (artificial opening)
through which faeces will be expelled.
N a v e l
Position of the stoma
A colostomy bag is attached over the stoma to
collect faeces. After a bowel movement, it is
either replaced or emptied.
L a r g e in t e s t i n e
P o s s i b l e s i t e s
o f c o l o s t o m y
o p e n i n g s
S m a l l i n t e s t in e
D i s e a s e d p a r t o f
r e c t u m r e m o v e d
If-
p
*,
:
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. : ' / '
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O p e n e n d o f
n
c o l o n b r o u g h t
t h r o u g h t o
s k i n s u r f a c e
Permanent colostomy
186
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