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Official Description

Colonoscopy, flexible; with endoscopic mucosal resection

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

A flexible colonoscopy with endoscopic mucosal resection (EMR) is a minimally invasive procedure that allows for the examination and treatment of lesions within the colon. During this procedure, a standard flexible colonoscope, which is a long, flexible tube equipped with a camera and light source, is inserted into the rectum and carefully advanced through the entire length of the colon, reaching the cecum or the terminal ileum. The use of air insufflation is critical as it helps to inflate the colon, separating the mucosal folds and enhancing visibility for the physician. This thorough examination enables the identification of any mucosal lesions present. Once a lesion is located, its borders are precisely marked using electrocautery, a technique that employs electrical current to create a controlled burn, ensuring clear delineation of the area to be treated. To facilitate the removal of the lesion, diluted adrenaline is injected into the submucosal layer surrounding the lesion. This injection serves to lift the mucosal layer, creating a space that separates the lesion from the underlying muscle tissue. Following this preparation, a snare with a suction cup is utilized to further detach the mucosal lesion from the surrounding tissue. The lesion is then excised and captured using the snare, after which the colonoscope is carefully withdrawn, completing the procedure. This technique is particularly effective for removing certain types of polyps and other abnormal growths, allowing for both diagnostic and therapeutic interventions during a single procedure.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The flexible colonoscopy with endoscopic mucosal resection (EMR) is indicated for various conditions and symptoms that necessitate direct visualization and potential removal of mucosal lesions within the colon. The following are the explicitly provided indications for this procedure:

  • Colorectal Polyps - The procedure is performed to identify and remove polyps that may be benign or have the potential to become malignant.
  • Colorectal Cancer Screening - EMR is indicated for patients undergoing screening for colorectal cancer, particularly when lesions are detected during routine colonoscopy.
  • Suspicious Lesions - The procedure is indicated for the evaluation and removal of lesions that appear abnormal or suspicious during a standard colonoscopy.
  • Gastrointestinal Bleeding - EMR may be indicated in cases where there is gastrointestinal bleeding suspected to be originating from a mucosal lesion.

2. Procedure

The procedure of flexible colonoscopy with endoscopic mucosal resection involves several critical steps that ensure both effective examination and treatment of mucosal lesions. The following outlines the procedural steps:

  • Step 1: Preparation and Anesthesia - The patient is positioned appropriately, and sedation is administered to ensure comfort throughout the procedure. This may involve the use of intravenous sedatives to minimize discomfort and anxiety.
  • Step 2: Insertion of the Colonoscope - A standard flexible colonoscope is gently inserted into the rectum. The physician carefully advances the scope through the colon, utilizing air insufflation to expand the colon and improve visibility of the mucosal surfaces.
  • Step 3: Visualization and Identification - As the colonoscope is advanced, the physician examines the entire circumference of the colon, looking for any abnormalities or lesions. Once a mucosal lesion is identified, its location and characteristics are noted.
  • Step 4: Marking the Lesion - The borders of the identified lesion are marked using electrocautery. This step is crucial as it delineates the area to be excised, ensuring precision during the removal process.
  • Step 5: Injection of Adrenaline - Diluted adrenaline is injected into the submucosal layer surrounding the lesion. This injection serves to lift the mucosal layer, creating a space that separates the lesion from the underlying muscle tissue, facilitating easier removal.
  • Step 6: Resection of the Lesion - A snare with a suction cup is employed to further detach the mucosal lesion from the surrounding tissue. The lesion is then excised and captured using the snare, ensuring complete removal.
  • Step 7: Withdrawal of the Colonoscope - After the lesion has been successfully removed, the colonoscope is carefully withdrawn from the colon, allowing for a final inspection of the mucosal surfaces to ensure no additional lesions are present.

3. Post-Procedure

Post-procedure care following a flexible colonoscopy with endoscopic mucosal resection involves monitoring the patient for any immediate complications, such as bleeding or perforation. Patients are typically observed in a recovery area until the effects of sedation have worn off. It is common for patients to experience mild cramping or bloating due to the air insufflation used during the procedure. Instructions for post-procedure care may include dietary modifications, such as starting with clear liquids and gradually reintroducing solid foods. Patients are advised to avoid strenuous activities for a short period and to report any unusual symptoms, such as severe abdominal pain, fever, or excessive bleeding, to their healthcare provider. Follow-up appointments may be scheduled to discuss pathology results from any lesions that were removed and to plan further management if necessary.

Short Descr COLONOSCOPY W/RESECTION
Medium Descr COLONOSCOPY FLX W/ENDOSCOPIC MUCOSAL RESECTION
Long Descr Colonoscopy, flexible; with endoscopic mucosal resection
Status Code Active Code
Global Days 000 - Endoscopic or Minor Procedure
PC/TC Indicator (26, TC) 0 - Physician Service Code
Multiple Procedures (51) 3 - Special payment adjustment rules for multiple endoscopic procedures apply.
Bilateral Surgery (50) 0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 1 - Statutory payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Endoscopic Base Code 45378  Colonoscopy, flexible; diagnostic, including collection of specimen(s) by brushing or washing, when performed (separate procedure)
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator Hospital Part B services paid through a comprehensive APC
ASC Payment Indicator Non office-based surgical procedure added in CY 2008 or later; payment based on OPPS relative payment weight.
Type of Service (TOS) 2 - Surgery
Berenson-Eggers TOS (BETOS) P8D - Endoscopy - colonoscopy
MUE 1
PT Colorectal cancer screening test; converted to diagnostic test or other procedure
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
GC This service has been performed in part by a resident under the direction of a teaching physician
SG Ambulatory surgical center (asc) facility service
51 Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
22 Increased procedural services: when the work required to provide a service is substantially greater than typically required, it may be identified by adding modifier 22 to the usual procedure code. documentation must support the substantial additional work and the reason for the additional work (ie, increased intensity, time, technical difficulty of procedure, severity of patient's condition, physical and mental effort required). note: this modifier should not be appended to an e/m service.
GA Waiver of liability statement issued as required by payer policy, individual case
CR Catastrophe/disaster related
53 Discontinued procedure: under certain circumstances, the physician or other qualified health care professional may elect to terminate a surgical or diagnostic procedure. due to extenuating circumstances or those that threaten the well being of the patient, it may be necessary to indicate that a surgical or diagnostic procedure was started but discontinued. this circumstance may be reported by adding modifier 53 to the code reported by the individual for the discontinued procedure. note: this modifier is not used to report the elective cancellation of a procedure prior to the patient's anesthesia induction and/or surgical preparation in the operating suite. for outpatient hospital/ambulatory surgery center (asc) reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
76 Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
KX Requirements specified in the medical policy have been met
33 Preventive services: when the primary purpose of the service is the delivery of an evidence based service in accordance with a us preventive services task force a or b rating in effect and other preventive services identified in preventive services mandates (legislative or regulatory), the service may be identified by adding 33 to the procedure. for separately reported services specifically identified as preventive, the modifier should not be used.
52 Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
58 Staged or related procedure or service by the same physician or other qualified health care professional during the postoperative period: it may be necessary to indicate that the performance of a procedure or service during the postoperative period was: (a) planned or anticipated (staged); (b) more extensive than the original procedure; or (c) for therapy following a surgical procedure. this circumstance may be reported by adding modifier 58 to the staged or related procedure. note: for treatment of a problem that requires a return to the operating/procedure room (eg, unanticipated clinical condition), see modifier 78.
74 Discontinued out-patient hospital/ambulatory surgery center (asc) procedure after administration of anesthesia: due to extenuating circumstances or those that threaten the well being of the patient, the physician may terminate a surgical or diagnostic procedure after the administration of anesthesia (local, regional block(s), general) or after the procedure was started (incision made, intubation started, scope inserted, etc). under these circumstances, the procedure started but terminated can be reported by its usual procedure number and the addition of modifier 74. note: the elective cancellation of a service prior to the administration of anesthesia and/or surgical preparation of the patient should not be reported. for physician reporting of a discontinued procedure, see modifier 53.
77 Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
78 Unplanned return to the operating/procedure room by the same physician or other qualified health care professional following initial procedure for a related procedure during the postoperative period: it may be necessary to indicate that another procedure was performed during the postoperative period of the initial procedure (unplanned procedure following initial procedure). when this procedure is related to the first, and requires the use of an operating/procedure room, it may be reported by adding modifier 78 to the related procedure. (for repeat procedures, see modifier 76.)
79 Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.)
AG Primary physician
AQ Physician providing a service in an unlisted health professional shortage area (hpsa)
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GW Service not related to the hospice patient's terminal condition
GZ Item or service expected to be denied as not reasonable and necessary
PN Non-excepted service provided at an off-campus, outpatient, provider-based department of a hospital
Q0 Investigational clinical service provided in a clinical research study that is in an approved clinical research study
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
Q6 Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
RT Right side (used to identify procedures performed on the right side of the body)
TP Medical transport, unloaded vehicle
X4 Episodic/focused services: for reporting services by clinicians who provide focused care on particular types of treatment limited to a defined period and circumstance; the patient has a problem, acute or chronic, that will be treated with surgery, radiation, or some other type of generally time-limited intervention; reporting clinician service examples include but are not limited to, the orthopedic surgeon performing a knee replacement and seeing the patient through the postoperative period
XE Separate encounter, a service that is distinct because it occurred during a separate encounter
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2017-01-01 Changed Moderate (Conscious) Sedation flag removed. See new Moderate Sedation category.
2015-01-01 Added Added
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