Colonoscopy
Scott M. Strayer, MD,
MPH
Associate Professor
University of Virginia
Health System
Department of Family
Medicine
A Case
• 45 yo male presents with rectal bleeding
X1.
• Physical exam reveals small nonthrombosed hemorroid.
• What other history would you like to
have?
• Are any further tests warranted?
One more case
• 50 year old presents for physical exam.
• What questions would you ask to
determine preferred method of colon
cancer screening.
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 50
(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]
Is there enough time for
prevention?
• Patient panel of 2500
• Age and sex distribution similar to US pop.
• To fully satisfy the USPSTF recs, it would
take 1067 hours per year or 4.4 hours per
working day of a physician’s time
• If you include children and pregnant women:
1621 hours per year / 6.8 hours per day
Priorities among recommended clinical
preventive services
Services
CPB
CE
Total
Childhood vaccinations
5
5
10
Adult tobacco cessation counseling *
5
4
9
Vision screening > 65 yrs *
4
5
9
Pap test, sexually active > 18 yrs
5
3
8
Colorectal cancer screening > 50 yrs *
5
3
8
Newborn metabolic screen
3
5
8
Hypertension screening
5
3
8
Influenza vaccine > 65 yrs
4
4
8
Lipid screening; men 35-65; women
45-65
5
2
7
Pneumovax >65 yrs *
2
5
7
Priorities among recommended clinical
preventive services
Services
Assess /counsel adolescents on
alcohol/drugs*
Adolescent tobacco cessation
counseling *
Chlamydia screening women 15-24
yrs *
Problem drinking screening /
counseling *
CPB
CE
Total
3
5
8*
4
4
8*
3
4
7*
4
3
7*
Breast cancer screening 50 – 69 yrs
4
2
Rubella
1
1
Coffield
AB,screening/vaccination
Maciosek MV, etal. Am J PrevinMed 2001;21(1):1-9.
women
6
2
Is it cost effective?
• Flex sig with FOBT Q 5 years-$92K per
life year saved.
• Pap smears Q year-$99K per life year
saved.
• Annual mammogram (55-64)-$132K per
life year saved.
Frazier AL, Colditz GA, Fuchs CS, Kuntz KM. Cost-effectiveness
Of screening for colorectal cancer in the general population.
JAMA 2000:1594-1961.
New Developments
Pignone M, Levin B. Recent Developments in Colorectal Cancer Screening and Prevention. American Family
Physician 2002:297-302.
Screening Capacity
• National screening program would
require approx. 10m procedures (double
current levels) annually or 5m
colonoscopy procedures (increase of
20%).
• Not enough surgeons and GI’s to
perform the additional colonoscopies.
Indications
• 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 cardiopulmonary 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
•
•
•
•
•
•
•
Light source
Suction apparatus
Biopsy forceps
K-Y Jelly
4X4 inch gauze pads
Nonsterile gloves
Water container (for suction)
More equipment
•
•
•
•
•
Video unit and monitor
Anoscope
Basin of water
Formalin jars
Disinfecting cleaner
Complications
•
•
•
•
•
•
•
Bowel perforation (1-2/1000)
Complications from sedation
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
• Fleets phosphorous soda X 2 or Golytely
• Abx prophylaxis for high risk (e.g. hx of
endocarditis, prosthetic valves, vascular graft1st year)
• Clear liquids day before exam and of exam
• 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
•
•
•
•
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).
Sedation
• Versed and Fentanyl
• Continuous monitoring
• Reversal if needed
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.
• Most common place for perforations
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!!
Transverse Colon
•
•
•
•
After splenic flexure (often blind curve)
Triangular appearance
Fairly straight
Hepatic flexure (blue-brown area where
livers is in contact with bowel wall)
Ascending Colon
• Also triangular
• Advance to cecum by pulling back,
using suction, often releasing right lower
quadrant abdominal pressure
• Identify landmarks
– Ileocecal valve
– Appendiceal Orifice
– Terminal Ileum
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
What if Polyps are Found?
Be nice to your patient
• Suction air out before terminating
procedure!