<s>
Sigmoidoscopy	B-Algorithm
(	O
from	O
the	O
Greek	O
term	O
for	O
letter	O
"	O
s/ς	B-Application
"	O
+	O
"	O
eidos	O
"	O
+	O
"	O
scopy	O
"	O
:	O
namely	O
,	O
to	O
look	O
inside	O
an	O
"	O
s	O
"	O
/	O
"	O
ς	O
"	O
-like	O
object	O
)	O
is	O
the	O
minimally	O
invasive	O
medical	O
examination	O
of	O
the	O
large	O
intestine	O
from	O
the	O
rectum	O
through	O
to	O
the	O
nearest	O
part	O
of	O
the	O
colon	O
,	O
the	O
sigmoid	O
colon	O
.	O
</s>
<s>
There	O
are	O
two	O
types	O
of	O
sigmoidoscopy	B-Algorithm
:	O
flexible	B-Algorithm
sigmoidoscopy	I-Algorithm
,	O
which	O
uses	O
a	O
flexible	O
endoscope	B-Application
,	O
and	O
rigid	O
sigmoidoscopy	B-Algorithm
,	O
which	O
uses	O
a	O
rigid	O
device	O
.	O
</s>
<s>
Flexible	B-Algorithm
sigmoidoscopy	I-Algorithm
is	O
generally	O
the	O
preferred	O
procedure	O
.	O
</s>
<s>
A	O
sigmoidoscopy	B-Algorithm
is	O
similar	O
to	O
,	O
but	O
not	O
the	O
same	O
as	O
,	O
a	O
colonoscopy	O
.	O
</s>
<s>
A	O
sigmoidoscopy	B-Algorithm
only	O
examines	O
up	O
to	O
the	O
sigmoid	O
,	O
the	O
most	O
distal	O
part	O
of	O
the	O
colon	O
,	O
while	O
colonoscopy	O
examines	O
the	O
whole	O
large	O
bowel	O
.	O
</s>
<s>
Flexible	B-Algorithm
sigmoidoscopy	I-Algorithm
enables	O
the	O
physician	O
to	O
look	O
at	O
the	O
inside	O
of	O
the	O
large	O
intestine	O
from	O
the	O
rectum	O
to	O
the	O
left	O
side	O
of	O
the	O
colon	O
,	O
called	O
the	O
sigmoid	O
.	O
</s>
<s>
With	O
flexible	B-Algorithm
sigmoidoscopy	I-Algorithm
,	O
the	O
physician	O
can	O
see	O
intestinal	O
bleeding	O
,	O
inflammation	O
,	O
abnormal	O
growths	O
,	O
and	O
ulcers	O
in	O
the	O
descending	O
colon	O
and	O
rectum	O
.	O
</s>
<s>
Flexible	B-Algorithm
sigmoidoscopy	I-Algorithm
is	O
not	O
sufficient	O
to	O
detect	O
polyps	O
or	O
cancer	O
in	O
the	O
ascending	O
or	O
transverse	O
colon	O
(	O
two-thirds	O
of	O
the	O
colon	O
)	O
.	O
</s>
<s>
However	O
,	O
although	O
in	O
absolute	O
terms	O
only	O
a	O
relatively	O
small	O
section	O
of	O
the	O
large	O
intestine	O
can	O
be	O
examined	O
using	O
sigmoidoscopy	B-Algorithm
,	O
the	O
sites	O
which	O
can	O
be	O
observed	O
represent	O
areas	O
which	O
are	O
most	O
frequently	O
affected	O
by	O
diseases	O
such	O
as	O
colorectal	O
cancer	O
,	O
for	O
example	O
the	O
rectum	O
.	O
</s>
<s>
The	O
tube	O
is	O
called	O
a	O
sigmoidoscope	B-Algorithm
.	O
</s>
<s>
Bleeding	O
and	O
puncture	O
of	O
the	O
colon	O
are	O
possible	O
complications	O
of	O
sigmoidoscopy	B-Algorithm
.	O
</s>
<s>
Flexible	B-Algorithm
sigmoidoscopy	I-Algorithm
takes	O
10	O
to	O
20	O
minutes	O
.	O
</s>
<s>
The	O
colon	O
and	O
rectum	O
must	O
be	O
completely	O
empty	O
for	O
flexible	B-Algorithm
sigmoidoscopy	I-Algorithm
to	O
be	O
thorough	O
and	O
safe	O
,	O
thus	O
the	O
patient	O
must	O
drink	O
only	O
clear	O
liquids	O
for	O
12	O
to	O
24	O
hours	O
beforehand	O
.	O
</s>
<s>
Rigid	O
sigmoidoscopy	B-Algorithm
may	O
be	O
useful	O
in	O
ano-rectal	O
diseases	O
such	O
as	O
bleeding	O
per	O
rectum	O
or	O
inflammatory	O
rectal	O
disease	O
,	O
particularly	O
in	O
the	O
general	O
practice	O
and	O
pediatrics	O
.	O
</s>
<s>
The	O
sigmoidoscope	B-Algorithm
is	O
lubricated	O
and	O
inserted	O
with	O
obturator	O
in	O
general	O
direction	O
of	O
the	O
navel	O
.	O
</s>
<s>
A	O
bellows	B-Algorithm
is	O
used	O
to	O
insufflate	O
air	O
to	O
distend	O
the	O
rectum	O
.	O
</s>
<s>
Lateral	O
movements	O
of	O
the	O
sigmoidoscope	B-Algorithm
's	O
tip	O
negotiate	O
the	O
Houston	O
valve	O
and	O
the	O
recto-sigmoid	O
junction	O
.	O
</s>
<s>
Several	O
studies	O
have	O
shown	O
the	O
potential	O
benefits	O
of	O
sigmoidoscopy	B-Algorithm
in	O
detecting	O
colorectal	O
cancer	O
.	O
</s>
<s>
A	O
2010	O
British	O
study	O
showed	O
sigmoidoscopy	B-Algorithm
reduced	O
"	O
overall	O
colorectal	O
cancer	O
incidence	O
and	O
mortality	O
by	O
31	O
percent	O
"	O
,	O
and	O
"	O
incidence	O
of	O
cancer	O
in	O
just	O
the	O
lower	O
part	O
of	O
the	O
colon	O
(	O
or	O
distal	O
colon	O
)	O
was	O
reduced	O
by	O
approximately	O
50	O
percent	O
for	O
those	O
who	O
underwent	O
screening	O
compared	O
with	O
those	O
in	O
the	O
control	O
group.	O
"	O
</s>
<s>
The	O
study	O
also	O
showed	O
that	O
the	O
effect	O
was	O
persistent	O
—	O
a	O
single	O
sigmoidoscopy	B-Algorithm
reduced	O
cancer	O
rates	O
for	O
the	O
length	O
of	O
the	O
11-year	O
study	O
.	O
</s>
<s>
Although	O
generally	O
considered	O
quite	O
safe	O
,	O
sigmoidoscopy	B-Algorithm
does	O
carry	O
the	O
very	O
rare	O
possibility	O
of	O
tearing	O
of	O
the	O
intestinal	O
wall	O
by	O
the	O
instrument	O
,	O
which	O
could	O
require	O
immediate	O
surgery	O
to	O
repair	O
the	O
tear	O
;	O
in	O
addition	O
,	O
removal	O
of	O
a	O
polyp	O
may	O
sometimes	O
lead	O
to	O
localized	O
bleeding	O
which	O
is	O
resistant	O
to	O
cauterization	O
by	O
the	O
instrument	O
and	O
must	O
be	O
stopped	O
by	O
surgical	O
intervention	O
.	O
</s>
