This Local Coverage Determination (LCD) addresses the colonoscopies that are
NOT performed for colorectal cancer screening. Colorectal cancer screening is
a separate benefit with specific guidelines.  
  
Proctosigmoidoscopy is the examination of the rectum and sigmoid colon.  
  
Sigmoidoscopy is the examination of the entire rectum, sigmoid colon and may
include examination of a portion of the descending colon.  
  
Colonoscopy is the examination of the entire colon, from the rectum to the
cecum, and may include the examination of the terminal ileum or small
intestine proximal to an anastomosis. The colonoscope is inserted anally (or
through a stoma) and is advanced optimally through the large intestine under
direct vision, using the scope's optical system. See the Centers for Medicare
and Medicaid Services (CMS) Internet-Only Manual, Pub. 100-04, Medicare Claims
Processing Manual, Chapter 12, 30.1B Digestive System - Incomplete
Colonoscopies for the definition of Incomplete Colonoscopies.

 **Covered Indications:**

1\. For evaluation of an abnormality discovered on barium enema and/or other
imaging technique that is likely to be clinically significant, such as a
filling defect or stricture or an inadequate examination;

2\. For evaluation of unexplained gastrointestinal (GI) bleeding;  

  1. Hematochezia not thought to be from rectum or perianal source
  2. Melena of unknown origin
  3. Presence of fecal occult blood

3\. For unexplained iron deficiency anemia;

4\. For surveillance of colonic neoplasia;

  1. For examination to evaluate the entire colon for synchronous cancer or polyps in a patient with treatable cancer or polyps.
  2. For follow-up 1 year after surgery for treatment of colorectal cancer when the patient is identified as being at high-risk for colon cancer and is eligible for continued screenings at 24-month intervals.
  3. For follow-up at least 3-6 months after colonoscopic removal of a large sessile adenoma (i.e., greater than 2 cm in greatest dimension).
  4. For patients with Crohns colitis, chronic ulcerative colitis (UC), pancolitis of greater than 7 years duration or left-sided colitis of over 15 years duration (no surveillance needed for disease limited to rectosigmoid) may have a colonoscopy every 1-2 years for multiple biopsies to detect cancer and/or dysplasia.

5\. For chronic inflammatory bowel disease (IBD) of the colon (if a more
precise diagnosis or if a determination of the extent of activity of disease
will influence immediate management);

6\. For clinically significant diarrhea of unexplained origin with additional
findings (e.g., weight loss or negative stool cultures persisting for more
than 3 weeks);

7\. For intraoperative identification of the site of a lesion that cannot be
detected by palpation or gross inspection at surgery (e.g., polypectomy site
or location of a bleeding source);

8\. For evaluation of acute colonic ischemia/ischemic bowel disease;

9\. For evaluation of a patient with Streptococcus bovis (S. bovis)
endocarditis or bacteremia;

10 For treatment of bleeding from such lesions as vascular anomalies,
ulceration and neoplasia;

11\. For removal of a foreign body;

12\. For excision of colonic polyps;

13\. For decompression of pseudo-obstruction of the colon (Olgilvies
Syndrome) following a trial of neostigmine or cathartics or a documented
reason that this would be either unsafe or inappropriate for the beneficiary;

14\. For treatment of colonic volvulus or stricture;

15\. For evaluation of an unexplained, new onset constipation, refractory to
medical therapy;

16\. For evaluation of an anorectal polyp (adenomatous polyp only); or,

17\. For palliative treatment of stenosing, bleeding neoplasms (e.g., laser,
electrocoagulation, stenting).

 **Limitations:**  
  
Endoscopy is generally not covered for treating the indications below.
Additional documentation should be submitted indicating the medical necessity
of the procedure for review.

  * Chronic, stable, irritable bowel syndrome (IBS), or chronic abdominal pain. There are unusual exceptions in which colonoscopy may be done to rule out organic disease, especially if symptoms are unresponsive to therapy;
  * Acute diarrhea;
  * Hemorrhoids;
  * Metastatic adenocarcinoma of unknown primary site in the absence of colonic symptoms, when it will not influence management;
  * Routine follow-up of IBD (except for cancer surveillance in Crohns disease and chronic UC);
  * Routine examination of the colon in patients about to undergo elective abdominal surgery for non-colonic disease;
  * Upper GI bleeding or melena with a demonstrated upper GI source; or,
  * Bright red rectal bleeding with a convincing anorectal source on sigmoidoscopy and no other symptoms suggestive of a more proximal bleeding source.

Colonoscopy/Sigmoidoscopy/Proctosigmoidoscopy are generally not covered for:

  * Fulminant colitis;
  * Possible perforated viscus;
  * Acute severe diverticulitis; or,
  * Diverticulosis is not usually considered an indication for a diagnostic or therapeutic colonoscopy/sigmoidoscopy/proctosigmoidoscopy but may be reported on the claim when this condition is found to be the final diagnosis.

 **Other Comments:**

Limitation of liability and refund requirements apply when denials are likely,
based on either medical necessity or other coverage reasons. The
provider/supplier must notify the beneficiary in writing prior to rendering
the service if the provider/supplier is aware that the test, item or procedure
may not be covered by Medicare. The limitation of liability and refund
requirements do not apply when the test, item or procedure is statutorily
excluded, has no Medicare benefit category, or is rendered for screening
purposes.

**Background**

Rigid endoscopes have been used in medicine since the early 19th century.1
Around the middle of the 20th century, the diagnosis and treatment of colon
diseases started to make significant advancements. The development and
improvement of endoscopic tools of the lower GI tract, particularly flexible
fiber optic endoscopes of varying lengths (depending on most proximal area of
the colon to be visualized), served as an alternative to barium enemas for
visualization of colonic abnormalities. The flexible fiber optic endoscopes
allowed biopsies and the removal of polyps at proximal colonic locations
beyond the reach of rigid endoscopes that could previously only be achieved by
surgery.2-4 Rigid proctosigmoidoscopy has largely been replaced by flexible
endoscopy; however, rigid endoscopy may be used to evaluate the distal large
bowel and rectum. This allows relatively easy washout of blood in the distal
colon for visualization.5 Rigid proctosigmoidoscopy is believed by some to
provide more accurate localization of malignancies than fiber optic endoscopy
techniques.6-7

One of the early studies of colonoscopy suggested not only a therapeutic but
potential diagnostic advantage over imaging techniques. The study compared
findings on barium contrast enema radiography and colonoscopy for the first
700 patients to undergo a colonoscopy at a single institution.8 Colonic
neoplasia was the most common indication for colonoscopy, being present in 344
of the 700 patients. IBD was the indication in 133 patients. Other indications
in decreasing order of frequency included x-ray negative colonic bleeding,
IBS, x-ray negative diarrhea and obstruction. In a comparison of Malmo double
contrast barium enema findings vs colonoscopy findings, they noted that the
barium enema found 97% of polyps > 1 cm detected by colonoscopy, but only 78%
of small polyps. Conventional barium enema evaluation was less successful. In
cases of UC, they found that barium enema findings agreed with colonoscopy
with biopsy findings in 68% of the cases. However, 18% of cases were found to
have a substantial underestimate of the extent of disease with the barium
enema and the barium enema was normal for 14% of cases while colonoscopy and
biopsy revealed total colitis.

 **Evaluation of abnormal findings on radiography**

Anatomic abnormalities can be discovered or evaluated by either radiographic
techniques, colonoscopy, pathology or surgery where necessary.

An early study of the use of colonoscopy in patients with strictures diagnosed
using a barium enema at a time when laparotomy was the only method of
confirming and possibly treating the diagnosis, reported results on 160
strictures in 154 patients treated at a single institution.9 The authors noted
that in 104 cases in which radiologists were ready to make a probable
diagnosis prior to colonoscopy, the diagnosis was proven wrong in 52% of the
cases by the colonoscopy. In the 50 patients for whom the radiographic exam
did not suggest a clear diagnosis, the colonoscopy was able to establish a
diagnosis in all but 2. The authors estimated that surgery was avoided in over
half the series through the use of colonoscopy. Diagnoses evaluated included
suspected malignancy, polyps, and known or suspected IBD.

Since the publication of this study in 1975, newer imaging techniques have
become available including computed tomography (CT). A study of performance
characteristics of CT colonography in 300 patients referred for colonscopy
(both for screening and because of symptom evaluation) reviewed the diagnostic
sensitivity of CT colonography.10 CT colonography was performed prior to the
colonoscopy. The sensitivity of CT colonography was found to be 100% for
cancerous polyps, though only 77.5% for adenomas and 69.7% for all polyps. For
adenomas under 5 mm, the sensitivity of CT was 66.9% and was 59.1% for
detection of polyps under 5mm. False positives were also identified on CT
scan. Notably, the CT scan did not offer a technique for assessing the nature
of polyps seen and the nature of these polyps was determined using
colonoscopy.

A subsequent study of CT colonography as compared with colonoscopy for the
detection of neoplasia screening compared CT screening in 3120 consecutive
patients with colonoscopy screening in 3163 patients.11 Neoplasms under 5 mm
were not reported on CT and as such counted as not being detected. For
patients with polyps of at least 6 mm detected on CT, patients were offered a
same day colonscopy unless medically contraindicated. Among large polyps and
polyps with high grade dysplasia, detection rates were similar based on the 2
screening methods. Positive findings detected by CT scan in this study
required colonoscopy for further evaluation.

 **Hematochezia**

A study on the use of urgent colonscopy in the diagnosis and treatment of
severe hematochezia evaluated 80 consecutive inpatients and found that 74% of
the patients examined had bleeding in the colon.12 Of these 80 patients, 64%
had an intervention to control bleeding; 39% had a therapeutic endoscopy, 24%
had surgery, and 1 had a therapeutic angiography.  A more recent small
randomized controlled trial compared urgent colonoscopy for acute lower GI
hemorrhage to standard care.13 In this study, consecutive patients were
enrolled to a single institution with lower GI bleeding with significant blood
loss without upper GI or anorectal bleeding. All patients underwent an upper
endoscopy and an anoscopy and were considered for enrollment only if a
bleeding source was not identified on these exams. There were 50 patients
randomized to each treatment arm. Urgent colonoscopy was performed in the
treatment group while the standard care group used a decision tree approach
which culminated in either elective colonoscopy or angiographic hemostasis
followed by elective colonoscopy. A definite source of bleeding was in a
significantly greater percentage of the group treated with urgent colonoscopy
than those treated with standard care (which included elective colonoscopy),
42% vs 22% respectively. The most common definitively identified cause was
bleeding diverticula, though angioectasias and ischemic colitis were also
identified by colonoscopy as causes. In spite of the difference in the rate of
definitive diagnosis, there were no significant differences in the outcomes
evaluated, including early rebleeding, late rebleeding, mortality, hospital
length of stay, transfusion requirements or the need for surgery. Given the
similar outcomes, the authors concluded that the choice of treatment approach
should be based on local expertise.

Diverticular perforation is a concern in colonoscopy, but the role of
colonoscopy in the treatment of hematochezia in the setting of known
diverticulosis has been studied in 2 prospective series.14 A total of 121
patients who presented to the hospital with hematochezia and persistent
bleeding in the setting of diverticula were followed. The first 73 were
treated with medical management, including colonoscopic diagnosis of the
bleeding source, and they underwent hemicolectomy if severe bleeding returned
or persisted while in the hospital. Of these 73, 17 had diverticular bleeding
and were followed for the study. In the second series of 48 patients bleeding
was treated endoscopically with colonoscopic epinephrine injections or bipolar
probe coagulation for nonbleeding visible vessels. From this second series, 10
were found to have bleeding diverticula and were followed for the study. Among
the 17 patients with bleeding diverticula assigned to medical plus surgical
treatment if necessary, 6 patients had recurrent bleeding and underwent
surgical treatment with hemicolectomy. Of the 10 patients who were treated
with colonoscopy, there were no episodes of rebleeding and none required
hemicolectomy. With a median follow-up time of 36 months in the medical plus
surgical cohort and 30 months in the endoscopically treated cohort there were
no episodes of late rebleeding. The authors concluded that surgical treatment
of bleeding diverticula should be reserved only for patients who do not
respond to medical management and attempted endoscopic control of bleeding.

A clinical guideline from the American College of Gastroenterology (ACG)
recommends the use of colonoscopy as the first line diagnostic approach for
acute lower GI bleeding.

 **Anemia and Occult Fecal Blood**

GI sources of blood loss have been considered a possibility in patients with
iron-deficiency anemia. The diagnostic utility of endoscopy has been studied
in this population in a study of 100 patients with iron-deficiency anemia.15
In this study, 100 patients at a single institution who were referred to
gastroenterology for evaluation of iron-deficiency anemia were studied. The
study included 73 outpatients and 27 inpatients with a mean age of 60 years
who had iron-deficiency anemia. Patients underwent upper endoscopy as well as
colonoscopy. A significant lesion was found in 62 of the 100 patients, and a
likely source of bleeding was found on colonoscopy in 26 of the patients, 1 of
whom also had a significant finding on upper endoscopy. Colon cancer was the
most common cause, identified in 11 of the 26 patients with a significant
colonoscopy finding. Other causes identified in decreasing order of frequency
were polyp, vascular ectasia, colitis, cecal ulcer, and parasitic infection.
The authors recommended that site-specific symptoms guide diagnostic
investigations of GI blood loss sources. Evaluation of GI sources of blood
loss should be done first with colonoscopy and followed with upper endoscopy
if no colonic source is found in asymptomatic older patients.

In patients who test positive for fecal occult blood sources, the location and
cause of the bleeding source is an obvious diagnostic question. The ability of
endoscopy to answer this question was addressed in a study of 248 patients who
referred to a single institutions gastroenterology service and who had at
least 1 positive test for fecal occult blood.16 Patients with iron deficiency
anemia or obvious blood in the stool including melena or hematochezia were
excluded from the study. There were 409 patients screened for study inclusion,
and 248 were studied, of whom only 7 were hospitalized with the remaining
treated as outpatients. All patients underwent a colonoscopy followed by an
immediate esophagogastroduodenoscopy (EGD). Using this dual endoscopy
approach, 48% of patients had a potential source of bleeding identified
endoscopically with 28.6% having a source identified on the EGD and 21.8%
having a source identified on the colonoscopy (6 patients had a source on both
endoscopic approaches). The most common identified abnormality found with
colonoscopy was an adenoma > 1.0 cm, found in 11.7% of patients. Other
identified abnormalities, in descending order of frequency, included
carcinoma, colitis, vascular ectasia, ulceration and Trichuris trichuria.

 **S. bovis bacteremia and endocarditis**

Early cases series have suggested that S. bovis endocarditis is associated
with colonic disease. An early retrospective case series of 14 patients with
S. bovis bacteremia found that colon polyps were common in these patients.17 A
later prospective study of 29 patients with S. bovis septicemia prospectively
completed GI evaluations on 15 and did not complete evaluations on the other
14.18 Of the 15 who had complete evaluations, 8 were found to have colon
carcinoma and 2 had esophageal carcinoma. In the 14 who did not have complete
evaluations, 1 had stomach carcinoma, 1 had gastric lymphoma and 3 had poorly
characterized colonic masses. The majority of the patients had no GI symptoms.
In a subsequent study of 19 patients with S. bovis bacteremia, 14 of whom had
endocarditis, found that 2 patients had colon carcinoma and 1 had metastatic
gastric cancer.19

A recent study retrospectively reviewed all cases of S. bovis at 2 hospitals
in the same city, 1 community and 1 tertiary care.20 They identified 45
patients with S. bovis bacteremia of whom 26 had neoplasia. The most common
neoplasm was adenomatous polyps, which were found in 14 patients, but 3
patients had invasive colorectal cancer, and the remaining patients had cancer
at other bodily sites.

 **Treatment of retained colorectal foreign bodies**

Retained colorectal foreign bodies may be treated in a number of ways. An
early study reviewing a 10 year single institution with ingested foreign
bodies found that most ingested foreign bodies that reached the stomach passed
spontaneously without intervention, and surgical removal was necessary for
those that did not.21 However, numerous case series have reported dealing with
colorectal foreign bodies that were retained. Among them an early case series
reported on 28 retained foreign bodies, 5 of which caused rectal
perforation.22 Of the 23 patients in this series without a perforation, 4
required removal in the endoscopy suite without the need for surgery. In
patients without perforation, endoscopic evaluation of the mucosa was
performed following removal of the body to assess for mucosal injury. A more
recent series reviewed cases of retained colorectal foreign bodies in 86
patients (an 87th patient left against medical advice).23 Of these, 23
patients required treatment in the operating room with 17 examinations under
anesthesia and 8 laparotomies.  Bedside extraction was successful in 63
patients (5 patients treated by the emergency room staff and 58 patients
treated by the surgical service). A variety of techniques were used in bedside
removal including forceps removal, rigid sigmoidoscopy, manipulation with a
foley catheter, and enema. As might be expected, an important factor
associated with the need for laparotomy was the location of the foreign body,
with foreign bodies in the sigmoid colon significantly more likely to require
intervention in the operating room as compared with foreign bodies located in
the rectum.

No studies have assessed optimal foreign body removal technique, and numerous
methods have been described for attempting nonsurgical removal including but
not limited to endoscopy as described in several reviews.24-26

 **Ogilvies Syndrome (Colonic Pseudo-Obstruction)**

Historically, dangerously large colonic dilation was treated surgically, but
with the development of endoscopic techniques, nonsurgical intervention became
feasible. Kukora and Dent initially reported the use of colonoscopy in the
decompression of massive nonobstructive cecal dilation.27 In this early case
series, they report that the surgical endoscopy service at a single
institution encountered 6 patients over 3 years with this condition. One of
the patients was not successfully decompressed nonoperatively and died
following cecostomy. In the other 5 cases, a flexible fiber optic colonoscope
was used to successfully decompress the colon without return of dilation in
any of the cases. A larger case series was later published which described the
outcomes of 22 patients seen for colonic pseudo-obstruction.28 In this later
series, the colon was successfully decompressed with a colonoscopy in 19 of
the 22 cases and it was unsuccessful in 3 of the cases, of which 1
spontaneously resolved and the other 2 were treated surgically. Of the 19
patients successfully treated, there were 4 patients with recurrence, 2 of
which went on to surgical treatment and 2 of whom had resolution spontaneously
with repeat colonoscopy.

More recently, neostigmine has been demonstrated to have use in the treatment
of colonic pseudo-obstruction. A small controlled trial of 21 patients, 11 of
whom were randomized to neostigmine and 10 of whom were randomized to receive
a saline control, indicated that neostigmine may be a potential treatment
prior to colonoscopy.29 In this study, neostigmine was effective in providing
an immediate clinical response in 10 of the 11 neostigmine treated patients;
though 2 of the patients had a recurrence and went on to receive a
colonoscopy. Additionally, 2 patients who received neostigmine had symptomatic
bradycardia which was not experienced in the control group. The authors
concluded that neostigmine should be considered before colonoscopy.

 **Volvulus**

Volvulus is an emergency which has had a high rate of associated mortality for
decades.30-31 For decades, volvulus has been managed conservatively with an
enema or endoscopy being found as treatment options with technical adequacy,
though surgery is required in many cases due to the presence of nonviable
bowel in need of resection, inability to achieve decompression with non-
operative means, or to resect involved bowel for the treatment of
recurrence.32-35

There does not appear to be any large prospective trials comparing the
management approaches, though a recent large retrospective cohort study of
inpatient admissions in the United States has compared outcomes based on
treatment approach.31 This study evaluated data from 63,479 cases from 2002 to
2010 and found that nonsurgical treatment, mostly endoscopy, was used in 16.6%
of cases without follow-up surgery and a mortality rate of 6.41%. Surgically
managed patients had mortality rates ranging from 3.01% - 17.84% depending on
the operative technique. Notably, this was a retrospective data review, and as
such management technique may have been selected by the care team in part
based on a patients pre-procedural health or mortality risk.

 **Diarrhea**

Diarrhea is a nonspecific symptom that may be a presenting symptom in a number
of diagnoses that are best evaluated with endoscopy. A number of diagnostic
approaches to diarrhea have been applied, colonoscopy among them. Since
colonoscopy allows for direct visualization of the colonic mucosa and the
ability to obtain tissue samples for histopathologic analysis, it has been
studied as a diagnostic tool for diseases where macroscopic or microscopic
colonic appearance is suspected to have clinical utility.

A study of 809 patients without human immunodeficiency virus (HIV) who had
chronic non-bloody diarrhea, found colonic pathology in 15% of cases with
diagnosis from most to least frequent including microscopic colitis, Crohns
disease, melanosis coli, UC, other forms of colitis, and nodular lymphoid
hyperplasia.36 Another study of 167 patients with chronic diarrhea,
macroscopically normal colons and terminal ileums on endoscopy reported
histologic abnormalities in 68.5% of the cases.37 The majority of these
histologic abnormalities were of no importance (67.9%), but a significant
minority was of borderline or clear diagnostic importance showing inflammatory
changes or infection in 21.6% of the cases and possible inflammatory changes
or melanosis coli in 10.5% of the cases. A case series of 228 patients with
chronic diarrhea evaluated by colonoscopy, of whom 168 had ileoscopy as well,
showed that colonoscopy and biopsy yielded a specific histological diagnosis
in 31% of patients, with lymphocytic colitis the most common single diagnosis,
and Crohns disease and UC 2nd and 3rd most commonly diagnosed.38 An early
study of Crohns disease found that diarrhea was reported by nearly all
patients with this diagnosis.39

 **Constipation**

Constipation is a nonspecific symptom which may be caused by numerous
conditions, many of which do not require invasive management.

Constipation as a presenting symptom of abnormal colonoscopy findings has been
studied in a large database study.40 This study retrospectively reviewed a
Clinical Outcomes Research Initiative (CORI) database containing data from 400
endoscopists in 24 different states. Cases were selected based on presenting
symptoms. They identified 41,775 colonoscopies for constipation alone,
attributed to another source or for average-risk screening. The final group
was used as a control to compare risks of abnormal findings.  A significant
colonoscopy finding was defined as a polyp > 9mm and suspected malignant.
Patients who had constipation alone had a lower adjusted relative risk of
having a significant finding on the colonoscopy as compared with average-risk
controls with a relative risk of 0.79. However, constipation accompanied by
bleeding or weight loss was associated with a higher relative risk of an
abnormal colonoscopy finding than average-risk screening colonoscopy patients:
relative risk of 1.57 with anemia, 1.18 with hematochezia, 2.04 with a
positive fecal occult blood test (FOBT) and 1.72 with weight loss.

 **Excision of Polyps**

Early histologic evaluations of colon and rectal cancers that were contiguous
with benign tumor has for decades suggested that many colon and rectal cancers
arise from previously benign polyps or adenomas. It has also been known for
decades that incidence of malignancy was highly related to adenoma or polyp
size, with tumors > 2 cm in diameter being much more likely to demonstrate
malignancy than smaller polyps, and polyps under 1 cm rarely having
malignancy.41 This has led to the idea that polyp removal would reduce the
rates of colon cancer development.42

The notion that removal of polyps without clear evidence of malignancy would
lead to lower rates of colon cancer developing was empirically studied in a
cohort of 1418 patients.43 Patients in this cohort underwent colonoscopies
with polypectomy if any polyps were found. Patients who had at least 1 adenoma
were then followed with subsequent colonoscopies, and rates of colon cancer
development in this cohort were compared with 3 reference groups: Mayo Clinic
data, St. Marks Hospital data, and Surveillance, Epidemiology, and End
Results Program (SEER) data. Over the follow-up of up to 7 years, colon cancer
development was significantly less common in the cohort who received a
polypectomy, supporting the idea that removal of polyps has a therapeutic
benefit even prior to the development of malignancy.

 **IBD**

An early study of diagnostic features of IBD reviewed the cases of 357
patients who had 606 endoscopies.44 Histologic or surgical diagnosis was used
as the reference against which diagnosis based on macroscopic features on
colonoscopy was judged. Colonoscopy was found to show the correct diagnosis in
89% of cases.

Accurately diagnosing a patients inflammatory bowel condition may have a role
in patients depending on disease severity. While some immunosuppressants such
as steroids may be effective in the treatment of both illnesses, general
approaches to management are to use the mildest and safest medication which
adequately controls symptoms. As such, aminosaliclyates, which are recommended
as a first line therapy in the treatment of UC have been found to be minimally
effective in the management of Crohns disease. Alternatively, methotrexate,
which may help control disease severity in Crohns disease, has not been
proven to be effective in UC.45-46

 **Palliation**

Patients with colon cancer that cannot be definitively treated may require
palliation of symptoms. Surgical palliation may be needed in many such
patients, though emergent surgical treatment of malignant obstruction has been
associated with high mortality rates. As such, stenting has been proposed as a
potential treatment instead of surgery or as a possible bridge to elective
surgery later.

A large multi-center case series reported data for 201 patients treated for
incurable malignant colorectal obstruction.47 There was successful stent
placement in 184 patients who were followed for longer term outcomes. Early
clinical success with colonic decompression was achieved in 89.7% of these
patients. Longer term outcomes were reported based on an average of 115 days
of post-procedure follow-up. In this cohort, 77% of patients who had initial
clinical success had relief of colonic obstruction until death and 14% were
alive with functioning stents at the end of the study period. There were 9% of
patients with major late complications, most of which were due to
perforations.

A study designed to evaluate the specific role of malignant colon obstruction
management strategy on the oncologic management and chemotherapy
administration in patients, reported retrospective data obtained from a single
institution on 31 patients who received a self-expanding metal stent and 27
patients who underwent surgical treatment.48 The hospital length of stay was 8
days in the stent-treated group as compared to 13.5 days in the surgically
treated group. Additionally, hemotherapy was started 14 days following
stenting and 28.5 days following surgery. There was no significant difference
in mortality between the groups. The authors concluded that use of palliative
stenting allows patients to spend less time in the hospital and receive
chemotherapy sooner.

A meta-analysis of stent placement reported outcomes of 451 patients, 244 of
whom underwent attempted stent placement in 12 studies.49 Studies included
considered stent placement in comparison to open surgery. This meta-analysis
found that the stent-treated group had lower hospital lengths of stay,
mortality, medical complications and the long term need for a stoma. Patients
treated with stent placement tended to tolerate an oral diet sooner than those
treated with surgery.

A study of Medicare claims with more patients than any single study in the
above meta-analysis  compared colon stent placement to colostomy in malignant
colon obstructions using the Medical Provider Analysis and Review (MedPAR)
data set from 2007-2008. This study evaluated 778 colon stent placements and
5,868 hospitalizations.50 The use of claims data limited the variables that
could be examined, so a match case-control study based records from a single
institution was also performed to assess clinical outcomes. The case-control
study had 12 patients who had colon stent placement and 24 matched patients
who had a colostomy. In the MedPAR component of the study, the use of stenting
was associated with an 8 day length of stay as compared with a 12 day length
of stay in the colostomy group. In the case-control study, they found that
both stenting and colostomy were technically successful 100% of the time, but
length of stay post-procedure was longer in the surgically treated group and
significant hospital complications were more common in the surgically treated
group.

For patients with symptomatic bleeding and/or obstruction of the colon, who
are not candidates for surgical resection, electrocoagulation and
photocoagulation have long ago been shown to be viable treatment options.51-53

 **Acute Colonic Ischemia**

Acute colonic ischemia is associated with unfavorable outcomes and high
mortality rates.54 Common presenting signs and symptoms of large bowel
ischemia include rectal bleeding, abdominal pain, and diarrhea, clinical
features shared with a number of diagnoses above for which colonoscopy is also
indicated.55 With the advent of advanced imaging techniques, the diagnosis can
sometimes be made with angiography or non-invasive imaging alone when it is
clinically suspected, though all imaging techniques have significant
diagnostic limitations including demonstrating late findings, a lack of
correlation with bowel infarction, and difficulties in demonstrating small
vessel occlusion.54,56 As such, colonoscopy is another effective diagnostic
approach that may demonstrate milder clinical disease than can be seen in less
invasive diagnostic modalities.54,57-58 As reviewed above, colonoscopy also
has the ability to demonstrate the presence of other conditions that may
present with similar clinical features as large bowel ischemia.

Early studies of endoscopy have shown that it is a useful tool where direct
visualization of the colonic lumen and mucosa or the need to biopsy/excise
tissue in the colon is desired. As such, colonoscopy has generally been
applied to the diagnosis and treatment of conditions for which direct
visualization of the lumen or mucosa has utility or for which tissue removal
is necessary. In summary, colonic endoscopic techniques have been selected for
use based on technical considerations, which is largely a matter of device
capabilities. As such, the major evidence-based questions for clinical
coverage policy relate to the therapeutic utility of endoscopic tissue
sampling/excision or diagnostic yield of direct lumen and mucosa visualization
in various conditions including IBD. Despite the long history of the use of
lower endoscopy, few if any high quality studies exist to answer these
questions. However, this long history means that there are decades of clinical
experience in addition to the available limited research.

Early studies of large bowel endoscopy showed that it provides better
characterization of lesions in the GI tract than imaging does. In spite of the
fact that imaging has advanced significantly, research still suggests that
endoscopy allows better detection of small lesions and better characterization
of lesions than does imaging. Moreover, lesions that are thought to be
suspicious on imaging and warrant either biopsy or outright excision require
an additional procedure, either surgery or endoscopy. In essence, endoscopy
has established itself as a surgery-sparing technique for the evaluation of
suspicious lesions. Additionally, while abdominal imaging may help to detect
both intra- and extraluminal pathology, specialized imaging to assess
intraluminal or epithelial pathology in the colon prior to endoscopy does not
clearly add value to the care of patients for whom there is a high pretest
probability of an abnormality (e.g., patients getting a colonoscopy to
evaluate bothersome symptoms), as endoscopy will be needed regardless to
further evaluate or to treat any abnormalities found on imaging.  

Bleeding from the colon suspected based on either rectal blood or occult
anemia is a concerning condition, which colonoscopy may help to accurately
diagnose and treat. Colonoscopy allows a provider to visualize such bleeding
sources and in many cases treat them as well. Evidence has shown in the past
that colonoscopy is frequently able to identify a cause of both hematochezia
as well as blood loss that is not obvious and may be detected only on FOBT or
with iron studies and the diagnosis of iron deficiency anemia. While the
studies demonstrating this are of low to moderate quality, the findings among
them are consistent, leaving little doubt that colonoscopy is an appropriate
intervention in conditions where there is a clear reason to suspect colonic
blood loss.

An interesting relationship has been observed between S. bovis bacteremia and
endocarditis and colon cancer. While the pathophysiology of this relationship
is not well understood, case series of patients with S. bovis suggest that
this population has a higher than expected prevalence of colon cancer.

The management of foreign bodies in the colon or rectum is largely a matter of
technical feasibility. No specific maneuver or procedure has been shown to be
optimal. Rather, published case series have shown that clinicians have at
their disposal a number of available treatment options to retrieve foreign
bodies which may help achieve successful foreign body removal, endoscopy among
them.

Single arm studies of colonoscopy in the treatment of colonic pseudo-
obstruction have shown that this therapeutic method is generally effective,
though a newer paper reporting results of a small controlled trial provides
evidence supporting the use of neostigmine as a preferable first line
treatment.

For the treatment of volvulus, retrospective studies have demonstrated that
endoscopic treatment may be sufficient and offers a good first line treatment
for patients so as to avoid or delay surgery.

As the evidence summarized above shows and consistent with a statement by the
American Society for Gastrointestinal Endoscopy (ASGE), colonoscopy and
biopsies are important for the diagnosis of a number of conditions that could
cause chronic diarrhea, including infectious and inflammatory diseases.59
Therefore, colonoscopy is considered reasonable and necessary in the diagnosis
of diarrhea that is not self-limited and for which the diagnosis is not known.

In constipation, the available evidence does not suggest that colonoscopy
generally has a high diagnostic yield, so colonoscopy is generally appropriate
only in the presence of other concerning symptoms as well or as a diagnostic
modality when constipation is refractory and a diagnosis remains elusive.

Colonic polyps may be associated with bleeding or anemia, and research has
demonstrated that some polyps are precursors to carcinoma, and therefore
excision, which can be done endoscopically, reduces the risk of subsequent
cancer development.

IBD may be diagnosed by colonoscopy through direct mucosal visualization as
well as biopsies, thereby influencing medical therapy.

For patients with colon cancer without definitively treatable causing
symptoms, colonoscopy offers a treatment alternative to surgery, which appears
to allow patients to spend more time out of the hospital and return to normal
activity sooner, which may be particularly important depending on the
anticipated life expectancy of the patient.

In acute colonic ischemia, diagnosis can be challenging, especially early on,
and endoscopic visualization of the colon may allow a diagnosis of both
ischemia as well as severity of the disease so as to guide management in a
timely fashion.