CMS Colonoscopy/Sigmoidoscopy/Proctosigmoidoscopy Form

Summary Of Evidence

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reach of rigid endoscopes that could previously only be achieved by surgery.^2-4 Rigid proctosigmoidoscopy has largely been replaced by flexible endoscopy; however, rigid endoscopy may be used to evaluate the distal large bowel and rectum.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 institution’s 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

Ogilvie’s 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 patient’s 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, Crohn’s 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 Crohn’s disease and UC 2nd and 3rd most commonly diagnosed.³⁸ An early study of Crohn’s 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. Mark’s 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 patient’s inflammatory bowel condition may have a role in patients depending on disease severity. While some immunosuppressant’s 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 Crohn’s disease. Alternatively, methotrexate, which may help control disease severity in Crohn’s 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.

Analysis of Evidence

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.

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 Crohn’s 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 (Olgilvie’s 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 Crohn’s 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.