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Ingestible pH and Pressure Capsule

Policy Number: MP-379

Latest Review Date: March 2024

Category:  Medical                                                                


Measurement of gastrointestinal transit times, including gastric emptying and colonic transit times, using an ingestible pH and pressure capsule (SmartPill® GI Monitoring System) is considered not medically necessary and investigational for the evaluation of suspected gastroparesis, constipation or other gastrointestinal motility disorders.


An ingestible pH and pressure-sensing capsule (SmartPill® GI Monitoring System) measures pH, pressure, and temperature changes to signify passage of the capsule through portions of the gastrointestinal tract. It is proposed as a means of evaluating gastric emptying for diagnosis of gastroparesis, and colonic transit times for the diagnosis of slow-transit constipation.

Gastroparesis and Constipation

Gastroparesis is a chronic disorder characterized by delayed gastric emptying in the absence of mechanical obstruction. Symptoms of gastroparesis are often nonspecific and may mimic other gastrointestinal disorders. It can be caused by many conditions; most commonly it is idiopathic, diabetic or post-surgical.

Constipation is a chronic disorder involving infrequent bowel movements, sensation of obstruction, and incomplete evacuation. Many medical conditions can cause constipation such as mechanical obstruction, metabolic conditions, myopathies, and neuropathies. Diagnostic testing for constipation can aid in distinguishing between two categories of disorders, slow-transit constipation and pelvic floor dysfunction.


Gastric emptying scintigraphy is considered the reference standard for diagnosing gastroparesis. The patient ingests a radionuclide-labeled standard meal, and then images are performed at zero, one, two, and four hours postprandially to measure how much of the meal has passed beyond the stomach. A typical threshold to indicate abnormal gastric emptying is more than 10% of the meal remaining at four hours after ingestion.

Standard tests used in the evaluation of constipation include ingestion of radio-opaque markers and colonic transit scintigraphy. In the radio-opaque markers test, small markers are ingested over one or several days and abdominal x-rays are performed at four and/or seven days. The number of remaining markers correlates with the colonic transit time. In colonic transit scintigraphy, a radio-labeled meal is ingested, followed by scintigraphic imaging at several time intervals. The location of the scintigraphic signals correlates with colonic transit times.


The most recent literature review was updated through March 5, 2024.

Summary of Evidence

For individuals who have suspected disorders of gastric emptying or slow-transit constipation who receive diagnostic testing with an ingestible pH and pressure capsule, the evidence includes studies of test characteristics and case series of patients who have undergone the test. Relevant outcomes are test accuracy and validity, other performance measures, symptoms, functional outcomes, and health status measures. The available studies have provided some comparative data on the SmartPill ingestible pH plus pressure-sensing capsule and other techniques for measuring gastric emptying. This evidence primarily consists of assessments of concordance with available tests. Because the available tests (eg, gastric emptying scintigraphy) are imperfect criterion standards, it is not possible to determine the true sensitivity and specificity of SmartPill. The results of the concordance studies have revealed a moderate correlation with alternative tests, but have provided only limited additional data on the true accuracy of the test in clinical care. Evaluation of cases with discordant results would be of particular value and, ideally, these studies should be linked to therapeutic decisions and to meaningful clinical outcomes. The evidence to date on the clinical utility of testing is lacking, consisting of a small number of retrospective studies. It is not possible to determine whether there is net improvement in health outcomes using SmartPill vs standard diagnostic tests. The evidence is insufficient to determine the effects of the technology on health outcomes.

Practice Guidelines and Position Statements

American and European Neurogastroenterology and Motility Societies

The American and European Neurogastroenterology and Motility Societies issued a position paper on gastrointestinal transit evaluation in 2011. In this position paper, the wireless motility capsule is recommended by consensus for assessing gastric emptying, small bowel, colonic, and whole gut transit times in patients with suspected gastroparesis or gastrointestinal dysmotility in multiple regions. However, the position paper notes the clinical utility of identifying delays in small bowel transit times is unknown.

American Gastroenterological Association

The American Gastroenterological Association’s (AGA) 2013 guidelines on gastroparesis diagnosis and treatment indicate the wireless motility capsule testing requires validation before it can be considered as an alternative to scintigraphy for diagnosing gastroparesis. Gastric emptying scintigraphy is considered the best accepted method to test for delays in gastric emptying.

U.S. Preventive Services Task Force Recommendations

Not applicable.


SmartPill®, GI monitoring system, ingestible pH and pressure capsule


In 2006, an ingestible capsule (SmartPill® GI Monitoring System) was cleared for marketing by the U.S. Food and Drug Administration (FDA) via a 510(k) application, with the indication for use to evaluate delayed gastric emptying. Gastric emptying is signaled when the pH monitor in the capsule indicates a change in pH from the acidic environment of the stomach to the alkaline environment of the small intestine. For example, an increase of two or more pH units usually indicates gastric emptying, and a subsequent decrease of one or more pH units usually indicates passage to the ileocecal junction. While SmartPill does not measure 50% emptying time, it can be correlated with scintigraphically measured 50% emptying time. The capsule also measures pressure and temperature throughout its transit through the entire GI tract, allowing calculations of total GI transit time. In 2009, the FDA expanded the use of the SmartPill to determine colonic transit time for the evaluation of chronic constipation and to differentiate between slow versus normal transit constipation. When colonic transit time cannot be determined, small and large bowel transit times combined can be used instead. The SmartPill is not for use in pediatric patients.

This differs from esophageal pH monitoring for gastroesophageal reflux disease which measures pH levels in various ways such as through catheters, impedance or a temporarily implanted device such as the Bravo. The ingestible pH and pressure capsule (i.e., SmartPill®) also differs from the wireless capsule endoscopy (i.e., PillCam™), which is a capsule swallowed by the patient that transmits video images wirelessly.


Coverage is subject to member’s specific benefits.  Group-specific policy will supersede this policy when applicable.

ITS: Home Policy provisions apply

FEP: Special benefit consideration may apply.  Refer to member’s benefit plan.  


CPT Codes:


Gastrointestinal transit and pressure measurement, stomach through colon, wireless capsule, with interpretation and report


  1. Abell TL, Camilleri M, Donohoe K, et al. Consensus recommendations for gastric emptying scintigraphy: a joint report of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine. Journal of Nuclear Medicine Technology, 2008; 36(1): 44-54.
  2. Arora Z, Parungao JM, Lopez R, et al. Clinical utility of wireless motility capsule in patients with suspected multiregional gastrointestinal dysmotility. Dig Dis Sci. May 2015; 60(5):1350-1357.
  3. Camilleri M, Bharucha AE, et al. American Neurogastroenterology and Motility Society consensus statement on intraluminal measurement of gastrointestinal and colonic motility in clinical practice. Neurogastroenterol Motil, December 2008; 29(12): 1269-1282.
  4. Camilleri M, et al. ACG Clinical Guideline: Gastroparesis. Am J Gastroenterol Aug 2022; 117(8):1197-1220.
  5. Camilleri M, Parkman HP, Shafi MA, et al. American College of Gastroenterology Clinical Guideline: management of gastroparesis. AM J Gastroenterol 2013; 108: 18-37; 2012.
  6. Camilleri M, Thorne NK, Ringel Y et al. Wireless pH-motility capsule for colonic transit: prospective comparison with radiopaque markers in chronic constipation. Neurogastroenterol Motil 2010; 22(8):874-82, e233.
  7. Cassilly D, Kantor S, Knight LC, Maurer AH, et al. Gastric emptying of a non-digestible solid: assessment with simultaneous SmartPill pH and pressure capsule, antroduodenal manometry, gastric emptying scintigraphy. Neurogastroenterol Motil, April 2008; 20(4): 311-319.
  8. Green AD, Belkind-Gerson J, Surjanhata BC, et al. Wireless motility capsule test in children with upper gastrointestinal symptoms. J Pediatr. Jun 2013; 162(6):1181-1187.
  9. IOM (Institute of Medicine). 2011. Clinical Practice Guidelines We Can Trust. Washington, DC: The National Academies Press.
  10. Kahrilas PJ, Shaheen NJ, Vaezi MF et al. American Gastroenterological Association Medical Position Statement on the management of gastroesophageal reflux disease. Gastroenterology 2008; 135(4):1383-91, 91 e1-5.
  11. Kuo B, Maneerattanaporn M, Lee AA et al. Generalized transit delay on wireless motility capsule testing in patients with clinical suspicion of gastroparesis, small intestinal dysmotility, or slow transit constipation. Dig Dis Sci 2011; 56(10):2928-38.
  12. Kuo B, McCallum RW, Koch KL, et al. Comparison of gastric emptying of a nondigestible capsule to a radio-labelled meal in healthy and gastroparetic subjects. Aliment Pharmacol Ther, January 2008; 27(2): 186-196.
  13. Lee YY, Erdogan A, Rao SS. How to perform and assess colonic manometry and barostat study in chronic constipation. J Neurogastroenterol Motil. 2014 Oct 30;20(4):547-52.
  14. Maqbool S, Parkman HP, Friedenberg FK. Wireless capsule motility: comparison of the SmartPill GI monitoring system with scintigraphy for measuring whole gut transit. Dig Dis Sci 2009; 54(10):2167-74.
  15. Parkman HP, Hasler WL, Fisher RS and American Gastroenterological Association. American Gastroenterological Association technical review on the diagnosis and treatment of gastroparesis. Gastroenterology, November 2004; 127(5): 1592-1622.
  16. Rao SS, Camilleri M, Hasler WL et al. Evaluation of gastrointestinal transit in clinical practice: position paper of the American and European Neurogastroenterology and Motility Societies. Neurogastroenterol Motil 2011; 23(1):8-23.
  17. Rao SS, Kuo B, McCallum RW et al. Investigation of colonic and whole gut transit with wireless motility capsule and radioopaque markers in constipation. Clin Gastroenterol Hepatol 2009; 7(5):537-44.
  18. Rao SS, Mysore K, Attaluri A et al. Diagnostic utility of wireless motility capsule in gastrointestinal dysmotility. J Clin Gastroenterol 2011; 45(8):684-90.
  19. Stein E, Berger Z, Hutfless S et al. Wireless motility capsule versus other diagnostic technologies for evaluating gastroparesis and constipation: a comparative effectiveness review. Rockville (MD): Agency for Healthcare Research and Quality; 2013.
  20. Tougas G, Eaker EY, Abell TL, et al. Assessment of gastric emptying using a low fat meal: establishment of international control values. Am J Gastroenterol, June 2000; 95(6): 1456-1462.
  21. U.S. Food and Drug Administration (FDA). 510(k) Summary SmartPill GI Monitoring System.
  22. Wang WJ, Foong D, Calder S, et al. Gastric Alimetry Expands Patient Phenotyping in Gastroduodenal Disorders Compared with Gastric Emptying Scintigraphy. Am J Gastroenterol. 2024 Feb 1;119(2):331-341.


Medical Policy Group, August 2009 (1)

Medical Policy Administration Committee, August 2009

Available for comment August 21-October 5, 2009

Medical Policy Group, December 2010 – Added new code 0242T effective Jan 1, 2011

Medical Policy Group, January 2011

Medical Policy Group, January 2012 (1): Update to Descriptions, Policy, Key Points and References related to MPP update; policy statement investigational non-coverage expanded to include colonic transit time

Medical Policy Group, November 2012: 2013 Coding Update – Added Code 91112 effective 1/1/2013 & deleted code 0242T effective 1/1/2013

Medical Policy Panel, March 2013

Medical Policy Group, April 2013 (3): 2013 Updates to Description & Key Points; no change in policy statement

Medical Policy Panel, March 2014

Medical Policy Group, March 2014 (3):  2014 Updates to Key Points & References; no change in policy statement

Medical Policy Panel, March 2015

Medical Policy Group, March 2015 (4): Updates to Key Points and References.  No change to policy statement.

Medical Policy Panel, November 2015

Medical Policy Group, November 2015 (4): Updates to Key Points and References; no change to policy statement.

Medical Policy Panel, November 2016

Medical Policy Group, November 2016 (4):  Updates to Key Points; no change to policy statement.

Medical Policy Panel, November 2017

Medical Policy Group, December 2017 (4): Updates to Description, Key Points and Previous Coding section. CPT code 0242T (deleted 12/31/12) was removed from previous coding. No change to policy statement.

Medical Policy Panel, November 2018

Medical Policy Group, December 2018 (4): Updates to Key Points. No change in policy statement.

Medical Policy Panel, November 2019

Medical Policy Group, November 2019 (5): Updates to Key Points. No change in Policy Statement.

Medical Policy Panel, November 2020

Medical Policy Group, December 2020 (5): Updates to Key Points. No change to Policy Statement. Effective December 14, 2020: Active Policy but no longer scheduled for regular literature reviews and updates.

Medical Policy Group, March 2022 (5): Reviewed by consensus. No new literature identified that would alter coverage statement at this time. Minor update to Key Points and References.

Medical Policy Group, March 2023 (5): Reviewed by consensus. Updates to Key Points, and Benefit Application. No new literature identified that would alter coverage statement at this time.

Medical Policy Group, March 2024 (11): Reviewed by consensus. Updates to Key Points, Benefit Application and References. No new literature identified that would alter coverage statement at this time.

This medical policy is not an authorization, certification, explanation of benefits, or a contract. Eligibility and benefits are determined on a case-by-case basis according to the terms of the member’s plan in effect as of the date services are rendered. All medical policies are based on (i) research of current medical literature and (ii) review of common medical practices in the treatment and diagnosis of disease as of the date hereof. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment.

This policy is intended to be used for adjudication of claims (including pre-admission certification, pre-determinations, and pre-procedure review) in Blue Cross and Blue Shield’s administration of plan contracts.

The plan does not approve or deny procedures, services, testing, or equipment for our members. Our decisions concern coverage only. The decision of whether or not to have a certain test, treatment or procedure is one made between the physician and his/her patient. The plan administers benefits based on the member’s contract and corporate medical policies. Physicians should always exercise their best medical judgment in providing the care they feel is most appropriate for their patients. Needed care should not be delayed or refused because of a coverage determination.

As a general rule, benefits are payable under health plans only in cases of medical necessity and only if services or supplies are not investigational, provided the customer group contracts have such coverage.

The following Association Technology Evaluation Criteria must be met for a service/supply to be considered for coverage:

1. The technology must have final approval from the appropriate government regulatory bodies;

2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes;

3. The technology must improve the net health outcome;

4. The technology must be as beneficial as any established alternatives;

5. The improvement must be attainable outside the investigational setting.

Medical Necessity means that health care services (e.g., procedures, treatments, supplies, devices, equipment, facilities or drugs) that a physician, exercising prudent clinical judgment, would provide to a patient for the purpose of preventing, evaluating, diagnosing or treating an illness, injury or disease or its symptoms, and that are:

1. In accordance with generally accepted standards of medical practice; and

2. Clinically appropriate in terms of type, frequency, extent, site and duration and considered effective for the patient’s illness, injury or disease; and

3. Not primarily for the convenience of the patient, physician or other health care provider; and

4. Not more costly than an alternative service or sequence of services at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of that patient’s illness, injury or disease.