Gastrointestinal Motility Disorders, Diagnosis and Treatment (for Idaho Only)

Coverage Summary

This policy (Policy Number CS046ID.A) applies only to the state of Idaho (including Idaho Medicaid Plus) and is effective 2025-06-01. It provides coverage guidance for diagnostic evaluation and treatment of gastrointestinal motility disorders including constipation, fecal incontinence, and gastroparesis. The coverage stance is mixed: some interventions are described as proven and medically necessary when specific criteria are met (for example, Gastric Electrical Stimulation (GES) for refractory gastroparesis under defined conditions, and anorectal/rectal functional testing such as rectal manometry, rectal sensation/tone/compliance testing, and anorectal manometry), while other modalities are listed as not medically necessary / unproven (notably colonic manometry in many contexts, MRI defecography, cutaneous or body surface electrogastrography (EGG/BSGM), and ingestible vibrating capsule devices). The policy lists applicable procedure and HCPCS/CPT codes for reference and includes definitions, evidence summaries, and regulatory context to support determinations. (Scope and effective date: CS046ID.A, effective June 1, 2025.)

Medical-Necessity Criteria

Medically Necessary - Gastric Electrical Stimulation (GES)

GES therapy is considered proven and medically necessary when:

Indication: refractory gastroparesis that has failed other therapies OR chronic intractable (drug-refractory) nausea and vomiting secondary to gastroparesis of diabetic or idiopathic etiology

Document failure of other therapies and that gastroparesis is diabetic or idiopathic (provider must include this documentation when requesting GES). Billing/PA required for implantation/revision/removal codes.

Medically Necessary - Anorectal and Rectal Functional Testing

The following are proven and medically necessary for evaluation of colorectal function:

Rectal manometry

Rectal sensation, tone, and compliance test (rectal balloon distention)

Conventional defecography (e.g., fluoroscopic/evacuation proctography)

Consider sequencing guidance: perform ARM and balloon expulsion prior to defecography.

Anorectal manometry

Not Medically Necessary / Unproven Procedures

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

Not Medically Necessary/Unproven: Colonic manometry for evaluating colon motility

Evidence insufficient to define effectiveness and patient selection; may be considered only in specialized centers or research contexts.

Not Medically Necessary/Unproven: Magnetic Resonance Imaging (MRI) Defecography for evaluating constipation and anorectal or pelvic floor disorders

Insufficient evidence of superiority to conventional defecography; not covered as standard diagnostic in many situations.

Not Medically Necessary/Unproven: Cutaneous, mucous, or serosal electrogastrography, electroenterography, or body surface gastric mapping (e.g., Gastric Alimetry, G-Tech Gut Tracker) for diagnosing intestinal or gastric disorders including gastroparesis

Methods and clinical utility insufficient; considered experimental/insufficient for routine coverage.

Diagnostic and Testing Guidance

When to perform defecography

Guideline-based recommendations and conditional statements regarding use of defecography:

Sequencing before defecography: Perform anorectal manometry and rectal balloon expulsion test prior to defecography (AGA strong recommendation).

Defecography indicated when ARM and balloon expulsion results are inconclusive.

When to consider defecography: Consider defecography to identify anatomic abnormalities (rectocele, enterocele, intussusception, prolapse) when anorectal physiology testing is not diagnostic or when ARM and balloon expulsion are equivocal (ASCRS/ACG recommendations).

Use barium/evacuation proctography as first-line imaging per evidence; MRI may be considered in selected settings.

Role of colonic manometry / colonic motility testing

Summarized recommendations and evidence statements about colonic manometry:

Coding

Referenced / Applicable Procedure Codes (for reference only)mixed

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.
43647	Laparoscopy, surgical; implantation or replacement of gastric neurostimulator electrodes, antrum.
43648	Laparoscopy, surgical; revision or removal of gastric neurostimulator electrodes, antrum.
43881	Implantation or replacement of gastric neurostimulator electrodes, antrum, open.
43882	Revision or removal of gastric neurostimulator electrodes, antrum, open.
64590	Insertion or replacement of peripheral, sacral, or gastric neurostimulator pulse generator or receiver, requiring pocket creation and connection between electrode array and pulse generator or receiver.
64595	Revision or removal of peripheral, sacral, or gastric neurostimulator pulse generator or receiver, with detachable connection to electrode array.
72195	Magnetic resonance (e.g., proton) imaging, pelvis; without contrast material(s).
72196	Magnetic resonance (e.g., proton) imaging, pelvis; with contrast material(s).

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FDA / Device product codes and regulatory references citedmixed

MYE	FDA product code for cutaneous electrogastrography/related devices
FFX	FDA product code referenced for multiple GI device types including radiopaque markers and electrogastrography instruments
QTN	Vibrant system product code (use to search de novo clearance)
LNH	FDA product code for MRI systems (referenced for MRI defecography equipment)

Provider Actions & Billing Rules

Prior Authorization

Prior authorization for Implantable GES devices

Implantation or replacement of gastric neurostimulator electrodes and pulse generators require prior authorization per plan requirements when billed for the listed surgical and device procedure codes. This policy applies to Idaho (including Idaho Medicaid Plus).

43647
43648
43881
43882
64590
64595

Documentation Required

GES indication documentation

When requesting gastric electrical stimulation (GES) as medically necessary, document that other therapies have failed and that the gastroparesis etiology is diabetic or idiopathic (or that the patient has refractory gastroparesis).

Background and Evidence Summary

Background (Idaho scope): This policy applies to Idaho only and addresses diagnostic approaches and treatments for Constipation, Fecal Incontinence, and Gastroparesis. Diagnostic evaluation emphasizes objective testing and validated protocols — for example, gastric emptying scintigraphy is the reference standard for documenting delayed gastric emptying in symptomatic patients and standardized meal protocols and adequate imaging duration are required for interpretation. For anorectal and defecatory disorders the policy emphasizes performing objective anorectal physiology testing (digital rectal exam, balloon expulsion test, anorectal manometry) and using validated sequences (perform anorectal manometry and rectal balloon expulsion before defecography). Specific clinical coverage criteria, thresholds, and procedural requirements are provided in other sections of the policy.

Evidence source	Key finding
GES outcomes (cohorts and comparative studies)
Reported clinical response rates vary (example: 61.7% response at 24 months for GES in Gourcerol et al. 2023); comparative and cohort studies report mixed results versus G-POEM or gastrectomy and substantial device removal rates in some series.
Systematic reviews/HTA conclusions (Hayes, Lal, Levinthal/Bielefeldt)
Reviews conclude evidence is inconsistent and low quality; randomized studies provide limited confirmation and device removal rates ~7–12% reported; additional RCTs needed.
Anorectal manometry diagnostic performance
Meta-analysis: ARM sensitivity ~0.80 and specificity ~0.80 for fecal incontinence (Yeap et al. 2017); subgroup measures vary by parameter.
Barium defecography yields (Grossi et al. 2018)
High-grade intussuscepta 23.7% (95% CI 16.8–31.4); large rectoceles 15.9% (95% CI 10.4–22.2); enterocele 16.8%; perineal descent 44.4% in pooled barium defecography data.
MRD technical diagnostics (Pääkkö et al. 2022)
Video defecography (VD) fully diagnostic 96.9% vs MRD 45.3%; VD detected more enteroceles, intussusceptions, and rectoceles than MRD; MRD technical success lower.
ECRI Gastric Alimetry assessment (2024)
ECRI concluded published evidence for Gastric Alimetry is very low quality and clinical utility is not established; additional validation and clinical utility studies needed.
Vibrant trial (Rao 2023)
Phase III RCT: vibrating capsule vs placebo — 39.3% vs 22.1% achieved ≥1 CSBM/week (CSBM1); 22.7% vs 11.4% achieved ≥2 CSBMs/week (CSBM2); adverse events mild, 11% reported vibrating sensation.
Hayes emerging tech conclusions
Hayes Emerging Technology Report concluded additional published evidence is needed; a small sub-study showed no significant difference in colonic transit time vs sham; overall more evidence required.

Coverage Determinations (contextual — device/evidence summaries): Regulatory and device-status highlights summarized in the policy include:

- The Enterra Therapy System (gastric electrical stimulation) is available under an FDA Humanitarian Device Exemption (HDE) (approved March 31, 2000) for chronic, intractable (drug-refractory) nausea and vomiting secondary to diabetic or idiopathic gastroparesis in adults (IRB oversight required for HDE use).

- The Vibrant system (an ingestible vibrating capsule) received FDA Class II de novo clearance on 2022-08-26 for adults with chronic idiopathic constipation unresponsive to laxatives for at least one month; other vibrating capsule systems (e.g., VibraBot) are not FDA approved in the U.S.

- Instruments for cutaneous electrogastrography, electroenterography, and body surface gastric mapping are regulated as FDA Class II devices (product codes such as MYE or FFX cited).

- Several radiopaque markers for colonic transit testing are FDA approved (product code FFX), and MRI systems used for MRI defecography are listed under product code LNH in FDA databases.

Definitions

Term	Definition
Anorectal Disorders
Structural or functional abnormalities of the anorectum or pelvic floor.
Anorectal Manometry
Test to measure pressures of the anal sphincter muscles, rectal sensation, and neural reflexes needed for normal bowel movements.
Colonic Manometry
Functional test for severe constipation where a probe is inserted in the colon to measure pressure and motor activities.
Constipation
Infrequent or hard-to-pass bowel movements, hard stools, or incomplete bowel movement sensation; infrequent means less than three bowel movements a week.
Defecography
Fluoroscopic examination with real-time assessment of defecation mechanics using barium.
EGG
Non-invasive measurement of gastric myoelectrical activity using cutaneous electrodes (electrogastrography).
Fecal Incontinence
Inability to control bowel movements causing stool to leak unexpectedly from the rectum.
Gastroparesis
Digestive disorder with abnormal or absent stomach motility; also known as delayed gastric emptying.
MR Defecography
Noninvasive MRI to obtain images at stages of defecation to evaluate pelvic floor function.
Balloon expulsion test
A physiologic test where the patient attempts to expel a 50 ml water-filled balloon to assess evacuation ability.
BSGM
Noninvasive high-resolution mapping of gastric electrical activity (e.g., Gastric Alimetry) intended to phenotype gastric dysfunction.
CSBM
Complete spontaneous bowel movement.
HDE
Humanitarian Device Exemption — FDA pathway for devices treating rare conditions; requires IRB oversight.

Revision History

2025-06-01policy_createdLatest

New Medical Policy noted in Policy History with date 06/01/2025.