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Anorectal andColonic Evaluation
JasonS.Mizell andKaitlinDomek
2
Refer to Algorithm in Fig.2.1
A. In addition to the overall history regarding
general state of health, a detailed history
focusing on the timing (i.e., chronicity or
events surrounding the onset of symptoms)
allows formation of a differential diagnosis
based on questions related to rectal bleeding, pain, changes in bowel habits, systemic
symptoms, and signicant past medical
history.
B. An abdominal examination should be per-
formed, noting distension, tenderness, palpable masses, hernias, hepatosplenomegaly,
and previous surgical scars.
C. Anal inspection requires adequate lighting
and positioning of the patient in the left lateral or prone position. Inspect for abnormal
masses or tissue, color and condition of the
perianal skin, any scars, and abnormal shape
of the opening of the anus. A baseline anal
exam at rest and during coughing should be
conducted. Any soiling of either the perianal
skin or the undergarments should be noted.
Often, excoriations may be present that may
J. S. Mizell (*)
Colorectal Surgery Division, Department ofSurgery,
University ofArkansas forMedical Sciences,
Little Rock, AR, USA
e-mail: jsmizell@uams.edu
K. Domek
Department ofSurgery, University ofArkansas
forMedical Sciences, Little Rock, AR, USA
indicate dermatitis/pruritus or a history of
seepage. All skin tags and other irregularities
should be described and ultimately all of the
information gleaned from the inspection
should be diagrammed in the medical record.
D. Digital examination includes a prostate
examination in males and examination of the
posterior vaginal wall in females. The examination includes a full 360° sweep of the anal
canal and the lower rectum. Care should be
taken to feel the entire anal canal versus
quick entry and exit, as subtle lesions and
even ssures may be detected on digital
examination. Resting tone and muscle function on attempted defecation should be noted,
as should puborectalis tone and motion. The
patient should be asked to bear down to
descend the rectum towards the anal opening,
allowing for some mid-rectal abnormalities
(lesions, intussuscepting rectal wall) to come
into contact with the ngertip.
E. Anoscopy evaluates the anal canal: anoderm,
dentate line, hemorrhoidal area, and the
lower most rectal mucosa. A side-viewing
instrument is optimal, as any enlarged hemorrhoids can prolapse into sight. Conversely,
end-viewing instruments, such as a retroexed sigmoidoscope, reduce tissue away
from the anal orice. Each quadrant, including the three major hemorrhoidal sites as
well as potential anterior and posterior ssure sites, should be evaluated. In addition to
a written description of any ndings, a dia-
© Springer Nature Switzerland AG 2020
S. R. Steele etal. (eds.), Clinical Decision Making in Colorectal Surgery,
https://doi.org/10.1007/978-3-319-65942-8_2
7
8
J. S. Mizell and K . Domek
Other
studies
K. Colonoscopy L. Radiographic
M. CT Bleeding ContrastS. MRI T. Ultrasound
Endoanal
Q. Air contrast
N. CT
Endorectal
R. Water-soluble
O. Technetium
enema
P. Arterial
labeled scans
catheterization
A. History
exam
B. Abdominal
Office
exam
D. Digital
C. Anal
inspection
Fecal
E. Anoscopy
F. Rigid
H. Hemoccult
G. Flexible
proctoscopy
I. FIT
J. Stool DNA
sigmoidoscopy
Fig. 2.1 Algorithm for anorectal and colonic evaluation. FIT Fecal immunochemical test
2 Anorectal andColonic Evaluation
grammatic representation is helpful both to
other physicians and for subsequent reevaluations. In particular, non-operative
hemorrhoid therapy can be quantiably
monitored.
F. Rigid proctoscopy allows visualization of the
rectum and distal sigmoid. Its best use is for
measurement of the distance from the anal
verge or dentate line of rectal tumors and
evaluation of proctitis.
G. Flexible sigmoidoscopy allows inspection of
an additional 40–60cm of proximal sigmoid
and descending colon. It requires more special training and equipment than does rigid
examination. However, the ability to use
video is an added advantage. In addition to a
written description of any ndings, a diagrammatic representation and/or photos may
be helpful to other physicians and for subsequent re-evaluation. Specically, the
response to topical therapy for proctitis can
be quantiably monitored. Other uses include
pouchoscopy, rectal bleeding, or pain, and
this procedure may be performed in the clinic
or endoscopic center.
H. Hemoccult testing may be used to document
heme-positive stool or in conjunction with
proctosigmoidoscopy as a screening tool for
colorectal neoplasia. More specically for
FOBT, it is important to avoid certain food
products and medications during the testing
period as described in the specic instructions accompanying the cards, as a falsepositive or false-negative may result. The
sensitivity of a single gFOBT in detecting
cancer is in the range of 30–40%.
I. Fecal immunochemical test (FIT) also
detects occult blood in the stool. It has the
advantage of detecting occult blood limited
to the lower gastrointestinal tract. Its sensitivity in detecting colorectal cancer has been
reported to be approximately 73.8%.
J. Multi-target stool DNA tests detect muta-
tions and epigenetic changes in stool DNA
that may indicate the presence of colorectal cancer. The sensitivity of such tests for
the detection of colorectal cancer is 92.3%
and the specicity is 86.6%. The multi-
9
Fig. 2.2 Colonoscopy
target DNA test is superior to FIT in detecting cancer and advanced precancerous
lesions.
K. Colonoscopy allows for the complete visual-
ization of the colon (Fig.2.2). It is useful for
patients who have lesions noted by radiographic studies or by proctosigmoidoscopy;
a personal or family history of neoplasia,
unexplained anemia, lower GI/rectal bleeding, or hemoccult positive stools.
Additionally, colonoscopy is predominately
used in asymptomatic patients for screening
for colorectal malignancy, as well as in
patients with a history of inammatory bowel
disease for disease surveillance and colorectal cancer screening.
L. Radiographic studies are indicated in the
evaluation of acute GI bleeding, anastomotic
leaks, constipation, and incontinence. They
are also indicated when formal colonoscopy
cannot be completed and when staging rectal
cancers.
M. Computed tomography colonography uses
CT technology to reconstruct images of the
bowel wall and mucosa. Sedation is not necessary for this imaging modality, and it
avoids the risk of colonic perforation. It is
important to realize that bowel preparation is
still required. CT colonography is more sensitive in the detection of colorectal cancer in
symptomatic patients than barium enema. If
10
the CT colonography is positive, then this
result must be conrmed with colonoscopy.
N. In patients with acute GI bleeding, CT angi-
ography can help localize the bleeding. It can
detect bleeding at a rate of less than 0.5mL/
min. Limitations include the lack of therapeutic benet and exposure to radiation and
contrast media.
O. Technetium-labeled scans are useful only in
the actively bleeding patient for localization
or (to a lesser degree) lateralization of the
bleeding. The study has no therapeutic benet, but is noninvasive and allows detection of
0.1–0.5mL/min of blood loss. It also serves
to help focus angiography.
P. Selective visualization via mesenteric vessels
is an invasive procedure that requires arterial
catheterization. It allows detection of
≥0.5 mL/min of blood loss. The technique
very accurately localizes bleeding and may
also be therapeutic with either vasopressin
infusion or embolization.
Q. Air-contrast study is superior to the single-
column study. It is indicated for the detection
of colon cancer and diverticula in patients for
whom colonoscopy cannot be completed.
R. Water-soluble enemas are used when colonic
obstruction, pseudo-obstruction, or an acute
inammatory process is suspected (though
are typically avoided in conditions such as
toxic megacolon). It is also used to evaluate
for an anastomotic leak. However, watersoluble agents provide less detail than barium (Fig. 2.3). Contrast enemas are often
used to evaluate anastomoses in cases of low
anterior resection with proximal diversion
prior to ileostomy takedown.
S. Magnetic resonance has three main roles:
evaluation and staging of rectal neoplasia,
evaluation of pelvic anatomy, and assessment
of functional disorders (Fig.2.4). For rectal
neoplasms, particularly adenocarcinoma,
MRI is used preoperatively to assess T and N
stage and postoperatively to assess response
to treatment. Additionally, MRI provides
high quality imaging for evaluation of anatomy of the rectum, bony pelvis, pelvic soft
tissue and musculature, and urinary and
J. S. Mizell and K . Domek
Fig. 2.3 Water-soluble enema
Fig. 2.4 Magnetic resonance imaging (MRI)
reproductive organs. The resolution is superior to CT in this regard. Lastly, MRI can be
used to evaluate for functional and anatomic
disorders such as pelvic organ prolapse, cystoceles, urethroceles, rectoceles, enteroceles,
abnormal pelvic oor relaxation, rectal prolapse, and intra-rectal intussusception. It is
performed by placing contrast gel into the
2 Anorectal andColonic Evaluation
11
rectum and obtaining magnetic resonance
images at rest and during defecation. The
advantages of MR defecography include the
avoidance of radiation and the possibility to
obtain high-resolution images of the functional dynamics of the pelvic oor musculature and pelvic organs.
T. Endoanal ultrasound can evaluate anal sphinc-
ter defects in patients with incontinence. Its
role in staging of malignancy has been supplanted by rectal cancer protocol MRI.
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Physiologic Testing
KirstenBassWilkins andJosephR.Notaro
3
Refer to Algorithm inFig. 3.1
A. Fecal incontinence refers to the involuntary
loss of feces or atus. In population studies,
the reported overall prevalence of fecal incontinence approaches nearly 20% of women,
while the prevalence in males is not as well
dened. This percentage increases dramatically in nursing home residents and fecal
incontinence is a frequent factor in nursing
home placement. The etiologies of fecal
incontinence are numerous and therefore an
accurate history and physical examination are
an important rst step in assessing the possible causes.
B. A careful history is required focusing not
only on potential medical conditions predisposing to fecal incontinence, but also obstetric and surgical history. The patient is
questioned regarding medical conditions
leading to diarrhea or frequent stools such as
irritable bowel syndrome, inammatory
bowel disease, celiac disease, hyperthyroidism, lactose intolerance, radiation therapy,
etc. Patients are asked about constipation as
this may cause overow fecal incontinence.
Medical conditions causing neuropathy such
as diabetes and multiple sclerosis are occa-
K. B. Wilkins (*) · J. R. Notaro
Department ofSurgery, RWJ Barnabas Health,
Edison, NJ, USA
sionally an etiology of incontinence. Certain
medications may be associated with diarrhea,
specically diabetes medications, and create
problems with continence that formed stools
may not. Similarly, sugar-free foods containing sorbitol and excessive caffeine intake can
also cause loose stools resulting in loss of
control. Obtaining an obstetric history is
imperative as vaginal delivery is the leading
cause of fecal incontinence in women who
have had children. Delivery details such as
prolonged labor, episiotomy, lacerations, forceps/vacuum delivery, and large birth weights
are elicited as these are associated with a
higher rate of signicant sphincter defects.
Surgical history such as perirectal abscess
drainage, anal stula surgery, hemorrhoidectomy, previous sphincteroplasty, partial lateral internal sphincterotomy, and rectal
cancer surgery, may provide clues as to the
etiology of incontinence. In addition, patients
should be asked about anal intercourse and
anal trauma. Patients are questioned about
swelling in the anal area that may be associated with prolapsed internal hemorrhoids or
rectal prolapse. The patient is asked about the
consistency of stool that is leaked, the frequency of leakage, whether or not they need
to wear a pad because of the leakage, and the
impact of incontinence on lifestyle modication. These answers are used to score the
severity of the fecal incontinence. Several
© Springer Nature Switzerland AG 2020
S. R. Steele etal. (eds.), Clinical Decision Making in Colorectal Surgery,
https://doi.org/10.1007/978-3-319-65942-8_3
13
14
K. B. Wilkins and J. R. Notaro
Fig. 3.1 Algorithm for the initial evaluation and physiologic testing for fecal incontinence
scoring systems are available, but the most
commonly utilized scoring system is the
Cleveland Clinic Florida Fecal Incontinence
Score (CCF-FIS).
C. Physical examination of the anorectal area
may be undertaken in the left lateral or prone
jackknife position. Visual inspection is crucial and focuses on anal tone and anal pathology that may be associated with seepage that
the patient may perceive as incontinence such
as anal stula, prolapsed internal hemorrhoids, rectal prolapse, and condyloma. A
search for scars in the anal area and any distortion of the anal canal may correlate with a
history of previous anorectal surgery or episi-
otomy. In women, the perineal body is
assessed looking for any obvious thinning
that would be associated with a sphincter
defect. The perianal skin is grasped and
touched to assess overall sensation. Digital
examination reveals any masses or irregularities such as a rectocele and allows a subjective assessment of anal sphincter strength. In
addition, the patient is asked to squeeze the
examining nger. If rectal prolapse is suspected, but is not seen at rest, the patient is
asked to sit on the commode and Valsalva to
see if the prolapse can be produced. It is
important to note that upwards of 1/3rd of
patients may have concomitant pelvic oor
3 Physiologic Testing
15
defects. Anoscopy allows the assessment of
hemorrhoids and distal lesions. Rigid proctoscopy or exible sigmoidoscopy should be
done to evaluate signs of proctosigmoiditis
that could be associated with inammatory
bowel disease, or sexually transmitted disease. If the patient is of appropriate age or
symptoms warrant the exam, a full colonoscopy should be scheduled.
D. The complete history and physical examina-
tion should reveal whether or not the patient
has fecal incontinence from an anal sphincter
related cause which warrants further evaluation in the anal physiology laboratory or if the
patient has a condition that requires medical
or surgical therapy such as inammatory
bowel disease, radiation proctitis, anal stula,
hemorrhoids, or rectal prolapse.
E. Patients with true fecal/atal incontinence
may then be evaluated in the anal physiology
laboratory.
F. Anal manometry, endoanal ultrasound, and
pudendal nerve testing are easily performed
in the physiology laboratory. Each of these
modalities will be discussed below individually (Fig.3.2).
G. Anal manometry is used to examine the rest-
ing and squeeze pressures of the anal sphincter complex, the length of the high-pressure
zone, rectal sensation, and rectal compliance.
Two types of conventional manometry probes
are available including water-perfused and
solid-state catheters. A deated balloon is
present at the tip of the catheter. Manometry
is usually performed in the left lateral decubitus position with the knees exed. The catheter is inserted to 5–6cm into the rectum and
then rest and squeeze pressures are obtained
at each 1 cm mark as the catheter is pulled
distally. The patient is asked to hold the
squeeze as long as possible to evaluate for
fatigue. In the anal canal, normal resting pressures are above 40mmHg. Squeeze pressures
should be at least 100 mmHg. The highpressure zone is typically 2–3cm in length.
Men tend to have higher resting and squeeze
pressures and longer high pressure zones as
compared to women. After resting and
squeeze pressures have been recorded, balloon ination is performed to assess sensation and compliance. The balloon is inated
with the catheter in the anal canal. Air or
water is used to inate the balloon. First sensation by the patient is recorded and is normally approximately 20 ml. First urge to
defecate is usually between 80 to 120ml, and
maximum tolerable volume usually ranges
from 200 to 250 ml. Compliance may be
measured by dividing balloon volume by balloon pressure and a normal range is approximately 10ml/mmHg. The rectoanal inhibitory
reex is also assessed with balloon ination
but is more important in the evaluation of
constipation and is discussed below. Resting
pressure is predominantly a reection of the
strength of the internal anal sphincter while
the squeeze pressure reects the strength of
the external anal sphincter. Rectal sensation
may be low in conditions such as diabetic
neuropathy and may be increased in conditions such as inammatory bowel disease.
First urge to defecate may be high in those
with a rectocele or megarectum and may be
low in those with irritable bowel syndrome.
Maximum tolerable volume may be low and
compliance poor in those with diseases such
as scleroderma. High resolution anal manometry is available in certain settings and utilizes
a system with multiple sensors on a single
probe and can determine the pressures
throughout the anal canal without repositioning the catheter. This technique allows for
three-dimensional reconstruction of the anal
canal. While anal manometry is useful, manometric ndings do not always correlate with
the severity of fecal incontinence or the
response to therapeutic interventions.
H. Endoanal ultrasound can be very useful in
evaluating patients with suspected sphincter
defect including patients with a history of
vaginal delivery, previous anorectal surgery,
anal intercourse, or anal trauma. The patient
is typically positioned in the left lateral decubitus position with the knees exed. The
16
K. B. Wilkins and J. R. Notaro
Fig. 3.2 Gastrointestinal/anorectal physiology testing that is indicated for the evaluation of fecal incontinence versus
constipation
well-lubricated ultrasound cap is inserted into
the anal canal. Two and three dimensional
ultrasound scanners are available with a 7 or
10MHz rotating endoprobe that allows for a
360° evaluation of the anal sphincter complex. Older machines require manual withdrawal to assess the proximal and distal
extent of the sphincter complex, while newer
machines, have a crystal that can be moved
proximally and distally without moving the
probe. The anal canal is divided into proximal, middle, and distal aspects that are easily
identied on ultrasound. The proximal anal
canal is dened by the presence of the
puborectalis sling. The middle anal canal is
identied by the presence of the external and
internal anal sphincter complex. The distal
anal canal is distal to the internal anal sphincter and only the external anal sphincter is
visualized. The internal anal sphincter is easily identiable due to its hypoechoic nature
(black on ultrasound imaging). The puborectalis and external anal sphincter are hyperechoic (white on ultrasound imaging).
Ultrasound is used to assess for defects in
internal anal sphincter, external anal sphincter, and puborectalis muscle. The location as
well as the degree of the defect or defects is
recorded. The perineal body can also be
imaged and measurements obtained. Perineal
body measurements less than 1cm are typically associated with sphincter injury. The
presence of a sphincter injury alone may not
predict the severity of incontinence. For
3 Physiologic Testing
17
example, there may be occult sphincter injury
in nearly 35% of women after vaginal delivery. However, the degree of sphincter injury
in patients with fecal incontinence may be
very useful in guiding therapy. Anal magnetic
resonance imaging may also be used to visualize the anal sphincter complex, however the
expense and greater variability in interpretation make this technique less desirable.
I. Pudendal nerve terminal motor latency may
be obtained, but is of limited usefulness in the
diagnosis and management of fecal incontinence. The pudendal nerves innervate the
external anal sphincter. Pudendal nerve terminal motor latency (PNTML) is dened as
the time it takes from stimulation of the nerve
until sphincter contraction. Normal values are
in the range of 2.0 ± 0.2 ms. The exam is
undertaken with the patient in the left lateral
decubitus position with the knees exed as
close to the chest as possible. The examining
index nger is covered with a St. Mark’s electrode and rectal exam is performed. The index
nger is used to hook the levator muscle on
the left and right sides, respectively, at the
level of the ischiorectal spines. The electrode
is used to deliver the stimulus at which time
the levator will contract. The response is
recorded usually three times and the process
is repeated on the other side. The latency can
be prolonged due to neuropathy of various
etiologies including diabetes and stretch
injury from pregnancy or delivery.
J. Physiology testing will separate those patients
with sphincter defects who may be amenable
to surgical intervention versus individuals
without signicant sphincter defects. In all
patients, the rst intervention should be nonoperative consisting of dietary manipulation
and medical management. Patients should
keep a food diary and avoid foods that cause
loose stool such as lactose, caffeine, or sorbitol. They should be advised to be on a ber
rich diet with ber supplementation to bulk
the stools. Medications contributing to diarrhea should be switched to alternatives when
possible. Cholestyramine is useful as a bilebinding agents in patients with post-
cholecystectomy diarrhea. Loperamide and
lomotil decrease the amount of diarrhea, but
also increase tone in the internal anal sphincter. Local perineal skin care with barrier
creams is helpful in alleviating excoriation.
Tap water cleansing enemas may be useful to
reduce the number of episodes of incontinence in those with overow due to constipation or rectocele. Biofeedback should also be
considered as an initial therapy in all patients
assuming they have some ability to contract
the sphincter complex. Biofeedback aims at
not only improving sphincter strength but
also to increase rectal sensation. Several techniques are available to augment the sphincter
including injectables and radiofrequency
ablation. Injectable agents such as hyaluronic
acid dextranomer gel (to date, the only injectable agent approved by the FDA) may be
injected submucosally in the ofce setting in
those with mild fecal/atal incontinence.
Radiofrequency tissue remodeling (i.e.
SECCA) utilizes radiofrequency energy
delivery to the internal anal sphincter and
results in collagen contraction and subsequent remodeling and tightening of connective tissue. While controversial, there is some
data to suggest this process results in
improved control in select patients. Sacral
nerve stimulation is a good alternative in
those patients without a denable sphincter
defect who have not improved with dietary/
medical manipulation and biofeedback,
though is increasingly used as a rst-line
agent as well as those failures with biofeedback and non-operative therapy. The articial
bowel sphincter, stimulated graciloplasty, and
percutaneous tibial nerve stimulation are not
FDA approved at present. The magnetic anal
sphincter and the anal sling are two newer
therapeutic possibilities. Colostomy may be
offered to patients and may greatly increase
the quality of life.
K. In patients with sphincter defects multiple
surgical options are available. As mentioned
above, dietary measures and biofeedback
should be utilized in all patients as an initial
approach. In patients with well-dened ante-