ModifiedUnitedHealthcarePolicy CS046KY.11

Gastrointestinal Disorders Diagnostic Procedures (for Kentucky Only)

Policy governing coverage and medical necessity of selected gastrointestinal diagnostic procedures for UnitedHealthcare members in Kentucky, including statements on procedures considered unproven or not medically necessary and documentation requirements.

Policy Summary

PayerUnitedHealthcare

PolicyGastrointestinal Disorders Diagnostic Procedures (for Kentucky Only)

Policy CodePolicy CS046KY.11

Change TypeCoverage list revisionscoding updatesrelocated GES language

Effective DateApr 1, 2026

Next Review DateN/A

Key ActionEnsure medical records document prior anorectal testing (ARM, BET) and specific test protocols when requesting MRI defecography or document FLIP indication and measurements when FLIP is used.

SourceLink

POLICY UPDATE CHANGES

Title changed from 'Gastrointestinal Motility Disorders, Diagnosis and Treatment (for Kentucky Only)' to a new title.

Language pertaining to gastric electrical stimulation (GES) therapy was removed and relocated to a different UnitedHealthcare Medical Policy.

Removed language indicating rectal manometry, rectal sensation, tone, and compliance test, conventional defecography, and anorectal manometry are proven and medically necessary for evaluation of colorectal function.

Esophageal Mucosal Integrity Testing by electrical impedance (e.g., MiVu) and FLIP technology for diagnosing achalasia were added to the list of unproven and not medically necessary procedures.

Colonic manometry was removed from the list of unproven and not medically necessary procedures.

Examples of cutaneous/mucous/serosal electrogastrography and certain branded body surface gastric mapping devices were removed from the policy.

CPT codes 43499 and 76498 were added to Applicable Codes.

Multiple CPT/HCPCS codes (e.g., 43647, 43648, 43881, 43882, 64590, 64595, 74270, 76496, 91117, 91120, 91122, A9286, A9900, A9999, E1399) were removed from Applicable Codes.

Clarifying language about medical records documentation and that coverage is determined by federal, state, or contractual requirements was added.

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1state-specific (Kentucky)

5procedures unproven / not medically necessary

2CPT codes added

15+CPT/HCPCS codes removed

04/01/2026policy revision date

Coverage Criteria and Determinations

Procedures Considered Unproven / Not Medically Necessary

The following procedures are considered unproven and not medically necessary due to insufficient evidence of efficacy:

Unproven / Not Medically Necessary Procedures: Magnetic Resonance Imaging (MRI) Defecography for evaluating constipation and anorectal or pelvic floor disorders; cutaneous, mucous, or serosal electrogastrography, electroenterography, or body surface gastric mapping for diagnosing intestinal or gastric disorders including gastroparesis; esophageal mucosal integrity testing by electrical impedance for diagnosis of GERD, eosinophilic esophagitis (EoE), and nonacid reflux disease or for monitoring treatment response; Functional Lumen Imaging Probe (FLIP) technology for diagnosing achalasia.

Listed as unproven/not medically necessary due to insufficient evidence of efficacy.

FLIP / EndoFLIP

FLIP/EndoFLIP — supportive contexts

Appropriate/Supportive Uses: FLIP/EndoFLIP may be useful to evaluate patients with achalasia when manometry cannot be tolerated or completed and as a complementary tool to assess esophagogastric junction (EGJ) opening dynamics and esophageal wall stiffness.

Do not make a diagnosis or treatment decision based on FLIP assessment alone; utilize established protocols and complementary testing (e.g., manometry, barium esophagram).

Operational details: When used, document DI and cross-sectional area measurements at specified balloon volumes (e.g., measurements at 30 mL and 40 mL) and relate findings to management decisions; evidence is limited by small sample sizes, lack of long-term outcomes, and lack of comparison groups.

FLIP has limited penetrance outside specialized centers and lacks standardized protocols and data analysis methodology.

MRI defecography

MRI defecography — diagnostic role and limitations

When MRD is considered: Consider MRI defecography (MRD) for evaluation of pelvic floor disorders when prior anorectal physiological testing (anorectal manometry [ARM], rectal balloon expulsion test [BET]) is inconclusive or when additional anatomic detail is needed for preoperative planning.

Document prior ARM/BET and reason for selecting MRD over fluoroscopic defecography; MRD may be useful as a triage or adjunct test but not a replacement for evacuation proctography (EP) or fluoroscopic defecography where those remain reference standards.

Limitations and comparative performance: MRD shows variable sensitivity and lower technical diagnostic success compared with video/fluoroscopic defecography in some studies (e.g., VD technical fully diagnostic 96.9% vs MRD 45.3%) and may under-detect enteroceles, intussusception, and rectocele relative to fluoroscopy; MRD sensitivity improves when an evacuation phase is performed.

Systematic reviews conclude MRD does not replace EP as the reference standard and clinicians should be mindful of under-diagnosis risk and consider additional imaging as needed.

EGG / BSGM

EGG and BSGM — diagnostic and evidentiary stance

Current evidence: Conventional electrogastrography (EGG) and electroenterography lack consistent evidence of clinical utility for diagnosing gastric stasis or improving patient outcomes; emerging body surface gastric mapping (BSGM, e.g., Gastric Alimetry) demonstrates improved signal fidelity and stronger symptom correlations in comparative studies but lacks sufficient high-quality clinical utility studies showing improved patient-relevant outcomes.

Standardized recording, analysis, interpretation protocols and validation against reference standards (e.g., gastric emptying testing) are needed before broad diagnostic coverage; studies vary in meal preparation, recording duration, and analytic methods.

Study findings: Comparative studies report higher motility abnormality detection rates and better patient-level classification accuracy for BSGM versus EGG (e.g., BSGM detection 33.3% vs GET 22.7% in one study; Schamberg et al. reported BSGM patient-level accuracy 0.78–0.96 vs EGG 0.54–0.43), but sample sizes and heterogeneity limit generalizability.

Typical BSGM protocols in reported studies used a standardized meal (e.g., 482 kcal) and prolonged postprandial recording (e.g., 4 hours), which may not be uniformly adopted in practice.

Evidence summaries for diagnostic utility

Evidence-summary based considerations (no explicit coverage decision in these chunks).

BSGM / EGG evidence summary: Comparative studies and systematic reviews indicate BSGM outperforms traditional low-resolution EGG for symptom correlation and patient-level classification, but methodological heterogeneity, small sample sizes, and varying protocols limit conclusions about clinical utility and impact on outcomes.

Further large, standardized clinical validity and clinical utility studies are needed before changing coverage stance.

Mucosal Impedance (MI) testing evidence summary: Esophageal mucosal integrity testing by electrical impedance (e.g., MiVu) shows distinct impedance patterns among GERD, EoE, and non-GERD in small studies, but evidence reviews (Hayes, ECRI) find the clinical validity and clinical utility have not been established and additional larger studies are required.

MI testing is not for use as a sole diagnostic screening tool in available reviews and lacks sufficient data demonstrating impact on patient management or outcomes.

Summary of coverage criteria changes

Policy revisions updated which diagnostic and therapeutic procedures are considered proven, unproven, or not medically necessary.

Removed proven designations: Language indicating certain anorectal and colorectal physiologic tests (rectal manometry, rectal sensation, tone and compliance testing, conventional defecography, and anorectal manometry) are no longer stated as proven and medically necessary.

Referenced in the revision summary; full replacement criteria are not shown in these chunks.

Added unproven/not medically necessary: Esophageal mucosal integrity testing by electrical impedance (e.g., MiVu) and FLIP technology for diagnosing achalasia were added to the list of unproven and not medically necessary procedures.

Documented in the Summary of Changes dated 04/01/2026.

Removed from unproven list: Colonic manometry was removed from the list of unproven and not medically necessary procedures.

Documented in the Summary of Changes dated 04/01/2026.

The policy identifies several diagnostic procedures as unproven and not medically necessary due to insufficient evidence of efficacy. These explicitly include MRI defecography for evaluation of constipation and anorectal/pelvic floor disorders, cutaneous or mucosal electrogastrography/electroenterography and body surface gastric mapping for diagnosis of gastric disorders including gastroparesis, esophageal mucosal integrity testing by electrical impedance for GERD, EoE and nonacid reflux (including for monitoring treatment response), and Functional Lumen Imaging Probe (FLIP) technology for diagnosing achalasia. Coverage for these procedures is not supported by the available evidence as summarized in the policy.

Clinical guidance emphasizes that FLIP/EndoFLIP is a complementary tool rather than a standalone diagnostic test: clinicians should not make a diagnosis or treatment decision based solely on FLIP assessment and should use FLIP findings alongside manometry, barium studies, and established protocols. Likewise, electrogastrography and branded body-surface gastric mapping systems (e.g., Alimetry) currently lack sufficient high-quality evidence to replace established reference tests such as gastric emptying scintigraphy and are not supported as sole diagnostic replacements in routine clinical practice.

Professional guideline statements are cited to contextualize the evidence base: the AGA position statement and updates do not recommend electrogastrography (EGG) for diagnosis of gastroparesis, and recent ACG guidance notes that mucosal integrity testing is commercially available but not yet developed sufficiently to be addressed in the guideline. These guideline positions support the policy's stance that EGG and mucosal impedance approaches are not established standard diagnostic tools.

Policy revisions removed language about gastric electrical stimulation (GES) therapy from this document and relocated that therapeutic content to a separate UnitedHealthcare medical policy (see referenced related policy). The revision history documents this relocation and clarifies that GES is no longer discussed in this diagnostic policy.

Several specific diagnostic modalities are explicitly mentioned in the coverage criteria: MRI defecography is addressed as an imaging option for pelvic floor evaluation but is listed among unproven tests for certain indications; electrogastrography (EGG) and body surface gastric mapping are noted as lacking convincing evidence for routine diagnosis of gastric stasis or impacting outcomes; mucosal impedance (esophageal mucosal integrity) testing is listed as unproven for diagnosing GERD, EoE, or nonacid reflux; and FLIP/EndoFLIP is discussed as an adjunctive tool for assessing EGJ opening dynamics and esophageal wall stiffness but not as a sole diagnostic modality.

Electrogastrography (EGG) and electroenterography are considered investigational/unproven in this policy because available studies have not demonstrated consistent clinical utility or impact on patient-important outcomes. Systematic reviews and assessments have identified methodological heterogeneity, limited diagnostic validation against accepted reference standards, and insufficient evidence that EGG-guided care improves management or outcomes.

Several published studies and systematic reviews describe EGG as experimental or not supported for routine clinical practice beyond research. The policy references analyses that found inconsistent symptom correlations, variable EGG methodologies, and limited evidence to justify integration of EGG into standard diagnostic pathways for disorders such as functional dyspepsia or GERD.

The revision summary documents that esophageal mucosal integrity testing by electrical impedance (e.g., MiVu) and FLIP technology were added to the list of procedures considered unproven and not medically necessary for diagnosis of achalasia and related indications. The history also records code and definition updates and relocation of gastric electrical stimulation content to another policy.

Applicable Codes and Coding Notes

Referenced Procedure CodesCPT

0779T	Gastrointestinal myoelectrical activity study, stomach through colon, with interpretation and report.
0868T	High-resolution gastric electrophysiology mapping with simultaneous patient-symptom profiling, with interpretation and report.
43499	Unlisted procedure, esophagus.
72195	Magnetic resonance (e.g., proton) imaging, pelvis; without contrast material(s).
72196	Magnetic resonance (e.g., proton) imaging, pelvis; with contrast material(s).
72197	Magnetic resonance (e.g., proton) imaging, pelvis; without contrast material(s), followed by contrast material(s) and further sequences.
76498	Unlisted magnetic resonance procedure (e.g., diagnostic, interventional).
91132	Electrogastrography, diagnostic, transcutaneous.
91133	Electrogastrography, diagnostic, transcutaneous; with provocative testing.

Regulatory / FDA product and 510(k) identifiersmixed

MYE / FFX	FDA product codes referenced for cutaneous electrogastrography, electroenterography, and body surface gastric mapping instruments
QIS	Product code for MiVu Mucosal Integrity Testing System (searchable)
K230056	510(k) Premarket Notification for MiVu (Apr 25, 2023)
K170833	510(k) number for EndoFLIP System (Apr 17, 2017)

Applicable CPT Codes — addedCPT

43499	CPT code added (no description in chunk)
76498	CPT code added (no description in chunk)

Applicable CPT/HCPCS Codes — removedmixed

43647	CPT code removed (no description in chunk)
43648	CPT code removed (no description in chunk)
43881	CPT code removed (no description in chunk)
43882	CPT code removed (no description in chunk)
64590	CPT code removed (no description in chunk)
64595	CPT code removed (no description in chunk)
74270	CPT code removed (no description in chunk)
76496	CPT code removed (no description in chunk)
91117	CPT code removed (no description in chunk)
91120	CPT code removed (no description in chunk)

1–10 of 15

1/2

BSGM meal caloric load — study-specific parameter

Meal caloric load482 kilocalories (meal used in Gharibans et al. study)

Study populationAdults with chronic nausea and vomiting symptoms (Gharibans et al.), matched to controls

Protocol elementsFasting baseline followed by ingestion of the 482-kcal meal

BSGM postprandial recording duration — study-specific parameter

Postprandial recording duration4 hours (postprandial recording used in Gharibans et al. study)

Recording phases

Provider Actions, Prior Authorization, and Documentation

Billing Rule

Code Reference / Prior Authorization Implication

The following codes are provided for reference only and inclusion does not imply coverage or prior authorization approval. Providers should verify prior authorization requirements with the member's benefit plan and submit claims with appropriate supporting documentation.

Listing of a code in this policy does not guarantee reimbursement or coverage; other policies may apply.
Prior authorization implications vary by contract and state; check benefit plan for requirements.

Prior Authorization

Prior authorization: FLIP and MRD appropriate contexts

Prior authorization may be required per the member's benefit contract. FLIP (EndoFLIP) and MRI defecography (MRD) have distinct appropriate contexts: FLIP is an adjunctive tool for select upper GI assessments and should not be used alone to make diagnoses or guide definitive treatment decisions; MRD is generally a secondary or complementary imaging modality for defecatory disorders when anorectal manometry (ARM) and rectal balloon expulsion testing (BET) are inconclusive or when additional anatomic detail is needed for preoperative planning. Submit prior authorization requests with documentation of prior test results and rationale for escalation to MRD.

Background and Rationale

Background: Disorders such as constipation, fecal incontinence, and gastroparesis frequently require specialized diagnostic evaluation. While imaging and physiologic testing (for example, scintigraphic gastric emptying for gastroparesis) remain reference standards, alternative or adjunctive tests (EGG/BSGM, FLIP, mucosal impedance, MRI defecography) have been investigated. The policy emphasizes reliance on validated, standardized protocols and notes that available evidence does not support routine clinical use of EGG/BSGM or mucosal impedance testing to guide management or improve outcomes, and that MRI defecography and FLIP have specific, limited roles pending further validation.

Definitions and Test Descriptions

Achalasia — definition

DefinitionA primary esophageal motor disorder characterized by degeneration of the myenteric plexus, impaired relaxation of the esophagogastric junction (EGJ), and loss of organized peristalsis.

Clinical featuresImpaired EGJ relaxation and absent or disordered peristalsis in the esophageal body

Source guidanceDefinition from policy definitions (ASGE referenced)

Electrogastrography (EGG) — definition and brief description

DefinitionA noninvasive method that measures gastric myoelectrical activity using cutaneous electrodes placed on the abdominal skin over the stomach to generate an electrogastrogram (EGG).

PurposeUsed to record gastric electrical activity (research/adjunct) but lacks consistent evidence of clinical utility for diagnosing gastric stasis or improving patient outcomes.

Policy Revision History

2026-04-01policy_revisionLatest

Title changed from 'Gastrointestinal Motility Disorders, Diagnosis and Treatment (for Kentucky Only)' and multiple substantive coverage updates: removed/relocated gastric electrical stimulation language; removed language asserting certain anorectal/colorectal physiologic tests as proven and medically necessary; added Esophageal Mucosal Integrity Testing (e.g., MiVu) and FLIP technology to the list of unproven/not medically necessary procedures; removed colonic manometry from the unproven/not medically necessary list.

2026-04-01coding_update

Applicable CPT codes 43499 and 76498 were added, and multiple CPT/HCPCS codes (including 43647, 43648, 43881, 43882, 64590, 64595, 74270, 76496, 91117, 91120, 91122, A9286, A9900, A9999, E1399) were removed.

The Policy History notes administrative and substantive edits including a title change effective 04/01/2026, removal/relocation of gastric electrical stimulation content, additions of esophageal mucosal integrity testing and FLIP to the unproven list, and updates to applicable procedure codes and documentation expectations.

Policy Summary

PayerUnitedHealthcare

PolicyGastrointestinal Disorders Diagnostic Procedures (for Kentucky Only)

Policy CodePolicy CS046KY.11

Change TypeCoverage list revisionscoding updatesrelocated GES language

Effective DateApr 1, 2026

Next Review DateN/A

SourceLink

On This Page

Fasting baseline, meal ingestion, then continuous 4-hour postprandial recording for spectral and spatial analyses

Primary analysesSpectral and spatial biomarker analyses of fed-fasting power ratios and slow-wave organization

Coding — not applicable

Not applicableNot applicable

FLIP: complementary to other esophageal testing; not diagnostic alone.
MRD: consider only after ARM and rectal BET are inconclusive or when fluoroscopic defecography is not possible or additional soft-tissue detail is required.

Note

FDA clearance noted (informational)

FDA clearance or device regulatory status is informational only and is not a basis for coverage. Examples: the MiVu Mucosal Integrity Testing System received FDA De Novo clearance (Class II) in 2019 and a 510(k) in 2023; MRI systems used for MRD and devices for electrogastrography/electroenterography have relevant FDA product codes. Providers should reference FDA resources for device details.

FDA clearance does not imply the service is covered under member benefits.
Refer to the FDA 510(k)/De Novo database for device-specific information.

Documentation Required

Coverage and documentation expectations

Coverage is determined by federal/state/contractual requirements and applicable law. Medical records may be requested to determine if the requested service meets medical necessity criteria. Documentation that does not support medical necessity may result in denial or non-coverage.

Benefit coverage determined by applicable federal, state, and contractual rules.
Medical records supporting medical necessity must be legible and available upon request.
Absence of required documentation may result in claim denial or request for additional information.

Denial Risk

Lack of adequate medical records/documentation may result in denial

Insufficient or absent medical record documentation to support the medical necessity of the requested service may lead to denial or non-coverage. Providers should ensure complete, legible records are submitted with authorization requests and claims.

Lack of adequate documentation may trigger denial of prior authorization or claim.
Keep contemporaneous notes, relevant test results, imaging reports, and prior treatment attempts in the chart.

Documentation Required

FLIP not standalone

FLIP (EndoFLIP) should be used as a complementary measurement tool and not as a standalone diagnostic test. Clinical decisions and diagnoses should not be based solely on FLIP measurements; corroborating clinical assessment and other diagnostic testing are required.

Do not base diagnosis or definitive treatment solely on FLIP results.
FLIP may inform management when used within standardized protocols and in conjunction with other tests.

Prior Authorization

MRD as secondary test

MRI defecography (MRD) is typically considered a secondary test for defecatory disorders when anorectal manometry (ARM) and rectal balloon expulsion testing (BET) are inconclusive or when further anatomic detail is needed for preoperative planning. Fluoroscopic defecography often remains the preferred evacuation study when available and feasible.

Order MRD only after ARM and rectal BET are performed and inconclusive, unless contraindicated or fluoroscopic defecography is not feasible.
Document why MRD is needed and how previous testing was insufficient.

Denial Risk

Limited evidence may trigger denial

Limited and evolving evidence for certain technologies (e.g., esophageal mucosal integrity testing by electrical impedance, some FLIP indications) means coverage may be denied as not medically necessary. When evidence is limited for clinical validity or utility, prior authorization reviewers may request additional documentation or deny as experimental/unproven.

Esophageal mucosal integrity testing (e.g., MiVu) is designated as unproven/not medically necessary in this policy update and may be denied.
FLIP for diagnosing achalasia and other indications lacking robust evidence may be considered investigational based on contract and policy language.

Denial Risk

Documentation-related denials

Insufficient documentation supporting prior testing, indications, or protocols for investigational or specialized tests may result in prior authorization denial or claim non-payment. Provide complete records that demonstrate medical necessity and prior diagnostic pathway.

Incomplete documentation of prior tests (e.g., ARM, BET) or missing imaging reports may prompt denial.
Ensure operative notes, prior imaging, and prior therapy attempts are included when applicable.

Documentation Required

Medical Record Documentation

The patient's medical record must contain documentation that fully supports the medical necessity for requested services. Required elements include relevant medical history, physical examination findings, prior conservative treatments, results of pertinent diagnostic tests, and any specialist consultations. Records must be legible and available on request.

Include clinical indications, symptom duration and severity, and prior noninvasive treatments tried and failed.
Attach copies of prior test reports (ARM, BET, fluoroscopic defecography), imaging, and consultation notes.
Document the clinical question that the requested study is intended to answer.

Documentation Required

Document FLIP measurements

When FLIP/EndoFLIP is used, document the indication, measurement protocol, and quantitative results (e.g., distensibility index [DI], cross-sectional area [CSA]) including volumes used for distension and measurement sites. Note how FLIP findings will influence management and list corroborating tests.

Record DI and CSA values, distension volumes (e.g., 30 mL, 40 mL), measurement sites, and number of measurements taken.
Document contemporaneous EGD findings if performed during the same session and explain clinical impact of FLIP results.

Documentation Required

Document MRD protocol and prior testing

For MRI defecography (MRD), include the protocol used (e.g., evacuation phase performed), indication, prior diagnostic test results (ARM, rectal BET, fluoroscopic defecography if performed), and rationale for selecting MRD over other modalities. State whether MRD will inform surgical planning or change management.

Specify whether MRD included evacuation/evacuation-phase imaging; sensitivity is higher when evacuation is performed.
Provide prior ARM and rectal BET results and state why they were inconclusive.
Include clinical question (e.g., preoperative anatomic mapping) and how MRD results will impact treatment.

Documentation Required

Documentation of MI testing method and comparator tests

When mucosal integrity (MI) testing is performed, document the specific method/device, comparator tests performed (e.g., EGD, pH monitoring, biopsies), and how MI results will influence management. Given limited clinical validity and utility evidence, clearly justify the clinical rationale for use.

State device/product name (e.g., MiVu) and regulatory status in the record.
Document contemporaneous EGD findings, pH testing, histopathology, and how MI testing supplements or replaces these tests.
Explain how MI test results will alter patient management if used.

LimitationsHeterogeneous protocols and recordings, inconsistent symptom correlations, and insufficient validation against reference standards.

Functional Lumen Imaging Probe (FLIP) — definition and brief description

DefinitionA catheter-based endoscopic system designed to assess esophageal motility by measuring diameter and pressure during balloon distension to evaluate EGJ opening dynamics and esophageal wall stiffness.

Key measurementDistensibility Index (DI) and cross-sectional area (CSA) measured during volumetric distension (example volumes: 30 mL and 40 mL).

Clinical contextFDA-approved measurement tool; recommended as a complementary assessment and not to be used alone for diagnosis or treatment decisions.

Magnetic Resonance Defecography — definition and brief description

DefinitionA noninvasive MRI test that obtains images during stages of defecation to evaluate pelvic floor anatomy, dynamic motion, rectal evacuation, and pelvic muscle function.

Clinical roleConsidered when anorectal physiologic testing (ARM, BET) is inconclusive or when additional anatomic detail is needed for preoperative planning.

LimitationsSensitivity may be lower than fluoroscopic defecography for some findings; evacuation-phase MRD improves sensitivity compared to MRD without evacuation.

Distensibility Index (DI) — definition

DefinitionDistensibility Index (DI): measurement at the narrowest perimeter of the esophagogastric junction during volumetric distension reflecting EGJ opening dynamics.

How measuredCalculated from cross-sectional area and intrabag pressure during volumetric distension using FLIP/EndoFLIP devices.

Clinical useUsed to assess compliance of the lower esophageal sphincter and predict treatment response in achalasia (example: POEM outcomes), though studies have limitations.

EndoFLIP / FLIP — catheter-based tool description

Device typeCatheter-based, endolumenal tool (EndoFLIP/FLIP) that measures simultaneous pressure and diameter during balloon distension.

Measurements recordedCross-sectional area (CSA), pressure, and derived distensibility metrics at the EGJ during volumetric distension.

Usage guidanceAvailable since 2009; recommended as a complementary assessment to manometry and not to be used alone for definitive diagnostic or treatment decisions.

BSGM (Gastric Alimetry) — definition and brief description

DefinitionBody surface gastric mapping (BSGM) is a multielectrode, noninvasive method that records gastric myoelectrical activity with spatial and spectral analyses (also called gastric mapping).

Clinical findingsStudies report improved signal fidelity and symptom correlations compared to conventional single-channel EGG, enabling phenotyping of gastroduodenal disorders.

Evidence statusEmerging technology with promising comparative performance (e.g., Schamberg et al., Gharibans et al.) but lacks sufficient high-quality outcome studies to establish clinical utility.

BSGM description — high-resolution multi-channel gastric mapping definition

High-resolution mappingA high-resolution, multi-channel cutaneous recording method that provides spectral and spatial biomarkers of gastric electrical activity for phenotyping gastroduodenal disorders.

Advantages over EGGDemonstrates tighter frequency ranges, greater symptom correlations, and higher patient-level classification accuracy in comparative studies versus conventional EGG.

Research needsRequires standardized recording protocols, larger validation studies against reference standards, and clinical utility trials showing improved patient outcomes.

Mucosal Impedance (MI) testing — definition and description of method and purpose

DefinitionMucosal Impedance (MI) testing uses a balloon or catheter-based impedance measurement during esophagogastroduodenoscopy (EGD) to assess esophageal mucosal integrity patterns.

PurposeIntended to help differentiate GERD, eosinophilic esophagitis (EoE), and non-GERD conditions by identifying segmental impedance patterns along the esophagus.

Evidence and limitationsSmall studies show distinct MI patterns across conditions, but reviews conclude clinical validity and clinical utility are not yet established and additional studies are needed.

Achalasia (alternate entry) — definition added to definitions section

DefinitionA primary esophageal motor disorder characterized by degeneration of the myenteric plexus, impaired relaxation of the esophagogastric junction (EGJ), and loss of organized peristalsis.

Clinical relevanceIncluded as a defined term in the policy definitions section (text addition noted in revision history).

Source noteDefinition text added to the policy definitions (not present in all provided chunks).

Esophageal Mucosal Integrity Testing — definition added to definitions section

DefinitionAdjunct procedure performed during endoscopy using impedance-based measurements to assess esophageal mucosal integrity and assist in differentiating GERD, EoE, and non-GERD.

Clinical contextIntended as an adjunct to standard diagnostic tests; formal definition was added to the policy definitions section in the revision history.

Evidence notePolicy notes clinical validity and utility remain uncertain; additional studies are needed.

Functional Lumen Imaging Probe (FLIP) — definition added to definitions section

DefinitionA catheter-based endoscopic system to assess esophageal motility, EGJ distensibility, and related metrics (DI, CSA) during volumetric balloon distension; definition added to policy definitions.

Measurement focusSimultaneous pressure and diameter measurements to evaluate EGJ opening dynamics and esophageal wall stiffness.

Clinical guidanceShould be used as a complementary tool and not as the sole diagnostic modality.