Flexible Sigmoidoscopy
Scott M. Strayer, MD,
MPH
Assistant Professor
University of Virginia
Health System
Department of Family
Medicine
Colon Cancer
• 150,000 cases per year.
• 50,000 deaths annually.
• #2 cause of cancer mortality in nonsmoking males and females.
Screening
Recommendations
• The USPSTF strongly recommends that
clinicians screen men and women 50 years of
age or older for colorectal cancer. (A
recommendation)
• Good evidence that periodic fecal occult
blood testing (FOBT) reduces mortality from
colorectal cancer and fair evidence that
sigmoidoscopy alone or in combination with
FOBT reduces mortality. Insufficient evidence
that newer screening technologies (e.g.,
computed tomographic colography) are
effective in improving health outcomes.
Screening
Recommendations
•
• AAFP-No published standards or guidelines
for low-risk patients
• ACOG-After age 50, annual FOBT (DRE
should accompany pelvic examination);
sigmoidoscopy every 3 to 5 years
• ACS-After age 50, yearly FOBT plus flexible
sigmoidoscopy and DRE every 5 years or
colonoscopy and DRE every 10 years or
double-contrast barium enema and DRE
every 5 to 10 years
Screening
Recommendations
• AMA-Annual FOBT beginning at age
50, and flexible sigmoidoscopy every 3
to 5 years beginning at age 50
• AGA-FOBT beginning at age 59
(frequency not specified);
sigmoidoscopy every 5 years, doublecontrast barium enema every 5 to 10
years or colonoscopy every 10 years.
Screening
Recommendations
• CTFPHC-Insufficient evidence to recommend
using FOBT screening in the periodic health
examination of individuals older than age 40;
insufficient evidence to recommend
sigmoidoscopy in the periodic health
examination; insufficient evidence to
recommend screening with colonoscopy in
the general population
• USPSTF-After age 50, yearly FOBT and/or
sigmoidoscopy (unspecified frequency for
sigmoidoscopy)
The Evidence
• Screening for colorectal cancer reduces
cancer-related mortality at costs comparable
to other cancer screening programs. Given
an expected screening compliance rate of
60% and current costs of the various
procedures, annual rehydrated fecal occult
blood testing plus sigmoidoscopy every 5
years is most cost-effective. If the cost of
colonoscopy is reduced by 25% or more,
screening every 10 years with colonoscopy is
preferred by this model (LOE: 2b).
Frazier AL, Colditz GA, Fuchs CS, Kuntz KM. Cost-effectiveness of screening
for colorectal cancer in the general population. JAMA 2000;284:1954-61.
More Evidence
• 16% of colorectal cancers prevented with
FOBT.
• 34% of colorectal cancers prevented with flex
sig.
• 75% prevented with colonoscopy.
• Colonoscopy q 10 years was more costeffective than flex sigs q 5-10 (LOE:?).
Sonnenberg A, et al. Cost-effectiveness of colonoscopy in screening for
colorectal cancer. Ann Intern Med October 17, 2000;133:573-84.
Even More Evidence
• Screening with sigmoidoscopy: There is
evidence from case control studies, to
recommend that flexible sigmoidoscopy be
included in the periodic health examination of
patients over age 50 [B, II-2, III]. There is
insufficient evidence to make
recommendations about whether only 1 or
both of fecal occult blood testing and
sigmoidoscopy should be performed [C, I].
CMAJ 2001 Jul 24;165(2):206-8 [20 references]
Indications
• Mostly for screening.
• Should consider colonoscopy if:
previous polyps, family history of colon
cancer, rectal bleeding, hemoccult
positive stools, change in bowel habits,
protracted diarrhea, surveillance in
UC/Crohn’s, anemia, unexplained wt.
Loss/fevers, abdominal pain.
Contraindications
• ABSOLUTE
– Acute, severe cariopulmonary disease.
– Inadequate bowel prep.
– Active diverticulitis
– Acute abdomen.
– History of SBE or prosthetic valves with no
prophylaxis.
– Marked bleeding dyscrasia.
Contraindications
• RELATIVE
– Recent abdominal surgery (bowel or
pelvic).
– Active infection
– Pregnancy.
Equipment
Additional Equipment
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Light source
Suction apparatus
Biopsy forceps
K-Y Jelly
4X4 inch gauze pads
Nonsterile gloves
Water container (for suction)
More equipment
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Video unit and monitor
Anoscope
Basin of water
Formalin jars
Disinfecting cleaner
Complications
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Bowel perforation (1/10000)
Bleeding (increased risk with biopsy)
Abdominal distention and pain
Infection (SBE, infection from another
pt.)
• Vasovagal symptoms
• Missed disease
Increased
Complications
• Watch out for patients with previous
bowel or pelvic surgery, irradiation, or
diverticulosis.
• Caution with blind advancement (only
limited distances).
Patient Preparation
• Signed informed consent
• 2 fleets enemas (one 90 minutes prior,
and one 30 minutes) before procedure
• Clear liquids after evening meal
• Take laxative if chronic constipation
• Take normal medications (caution with
diabetics)
Clear Liquid Diet
• Beverages: carbonated, coffee, kool-aid
(avoid red), tea.
• Desserts: Jello, clear popsicles
• Fruit: Apple juice, cranberry juice,
grape juice
• Soups: Beef bouillon, clear broth
• Sweets: hard candy, sugar.
Anatomy Review
The Procedure
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Pt. Placed in left lateral decubitus position
Rectal examination first
Lubrication is key, don’t smear the lens
Either directly insert scope, or flex index
finger behind the scope.
• Hold scope in left hand, use thumb for up and
down, use right hand for right-left (or can also
use thumb).
Rectum
• Insert scope 7-15cm, insufflate and/or
withdraw to visualize lumen
• Normal rectal mucosa is a nonfriable,
vascular network.
• Proctitis produces an erythematous, friable
mucosa, often with bleeding.
• Semilunar valves of Houston appear as sharp
edges protruding into the lumen (there are 3)
with shadows noted behind them.
Rectum
• Ulcerative colitis will produce erythema,
friability, and mucosal bleeding.
Rectal Colon CA
Sigmoid
• Redundant folds, hard to visualize
lumen
• May have to: insufflate, extensive
turning, torquing, accordionization, or
dithering
• Avoid bowing out.
Techniques
FIGURE 1.Hooking and straightening technique used to pass through a
tortuous sigmoid colon. (A) The scope is inserted to the angled sigmoid.
(B) The scope tip is turned to a sharp angle, and the sigmoid is hooked
as the scope is withdrawn. (C) The sigmoid is straightened as the scope
is withdrawn. The scope can then be inserted through to the descending
Other Techniques
FIGURE 2.Paradoxic
insertion. (A) The scope is
bowing out the sigmoid
colon, which has a mobile
mesenteric attachment. (B)
Paradoxic insertion
describes the insertion of
the tube without
advancement of the scope
tip. Paradoxic insertion can
be very uncomfortable for
the patient.
Descending Colon
• Long, straight tube with concentric
haustrae.
• Vascularity is random, reticular.
• Polyps can either be mound-like
(sessile) or on a long stalk
(pedunculated).
• Don’t mistake suction polyps or mucous
for polyps!!
Pedunculated Polyp
Diverticulosis
Crohn’s Colitis
C. Difficile Colitis
The Final StepRetroflexion
• Accomplished by turning inner knob all
the way “up” and outer knob all the way
“right” while gently inserting and rotating
180 degrees.
• Make sure you are in rectum, and not to
far from internal sphincter.
Retroflexion with
Hemorrhoid and Small
Polyp
Be nice to your patient
• Suction air out before terminating
procedure!