Cairn Diagnostics, a provider of breath tests intended for routine use in diagnostic medicine, has announced that the U.S. Food and Drug Administration (FDA) has expanded the approval of the company’s13 C-Spirulina Gastric Emptying Breath Test (GEBT) to now include “at home” administration under virtual supervision of Cairn Diagnostics.

GEBT is an FDA-PMA approved, CE marked, Class III in-vitro diagnostic drug-medical device combinationi product used for measuring the rate of solid phase gastric emptying and identifying delayed gastric emptying, a condition known as gastroparesis, in patients ages 18 years and older. This breath test is non-invasive, orally administered, and standardized. It does not require nuclear medicine imaging equipment, specially licensed facilities or personnel, or radioactive material.

“GEBT is a non-radioactive, standardized method for helping diagnose gastroparesis, and our new virtual at-home telehealth administration option significantly expands access to this [breath] test on a more widespread scale – from rural communities to cities,” says Kerry Bush, president & COO, Cairn Diagnostics. “Telehealth, particularly during the COVID-19 pandemic, has emerged as a preferred option for healthcare providers. Our approach provides convenience, safety, and diagnostic expediency enabling physicians to complete a more rapid diagnostic workup and determine the best course of action to achieve improved health outcomes.”

Gastroparesis affects over 5 million people in the U.S.ii The stomach empties abnormally slowly and is defined by delayed gastric emptying in the absence of mechanical obstruction. This debilitating disease is characterized by recurrent symptoms such as nausea, vomiting, early satiety, postprandial fullness, abdominal discomfort, and pain. GEBT provides a more convenient, timely modality for assessing gastric emptying, particularly in susceptible populations such as diabetics, idiopathic gastroparetic patients, neurologically affected patients, and tender populations where radiation is best avoided. Examples include women of child-bearing age and patients needing more than one evaluation.

Conducting the Breath Test

Conducted over a 4-hour period after an overnight fast, the gastric emptying breath test (GEBT) is designed to show how quickly the stomach empties solids by measuring labeled carbon dioxide in a patient’s breath. The GEBT process is simple: a physician writes an order for the test, the Cairn telehealth administration team holds a welcome call with the patient, ships a kit to their residence, and uses a secure audio-video platform for communication. Cairn sends the patient a secure, web-based link for supervised virtual administration of the test, in which a Cairn certified technologist will coach and supervise the patient through the GEBT test administration procedure. The patient’s breath samples are sent back to Cairn’s CLIA certified lab in Brentwood, Tennessee via overnight courier. The physician receives a comprehensive gastric emptying report via a secure portal within 24-48 hours after receipt of patient breath samples.

GEBT was validated in FDA-approved, dual-labeled clinical validation studies (Mayo Clinic, Rochester) against the 4-hour radioactive Gastric Emptying Scintigraphy (GES) procedure, which is considered the conventional method of assessing gastric emptying and must be conducted in specially licensed nuclear medicine facilities.iii GEBT is also now included in recently published international consensus guidelines on the diagnosis and classification of gastric and intestinal motility disorders indicating that “13C-Spirulina GEBT may now be used alternatively to scintigraphy as a result of careful validation, high concordance with scintigraphic data, and the FDA’s approval of the test.” iv


i. FDA News Release April 6, 2015:

ii. Centers for Disease Control and Prevention. Long-term Trends in Diabetes. CDC’s Div Diabetes Transl. Published online 2014.

iii. Szarka L, et al. A stable isotope breath test with a standard meal for abnormal gastric emptying of solids in the clinic and in research. Clinical Gastroenterology and Hepatology. June 2008; 6(6):635-643. Available at

iv. J. Keller, G Bassotti, J Clarke, P Dinning, M. Fox, M Grover, P. M. Hellstrom, M Ke, P. Layer, C Malagelada, H. Parkman, S. M. Scott, J. Tack, M Simren, H. Tornblom, M. Camilleri, 2018. CONSENSUS STATEMENT: Advances in the diagnosis and classification of gastric and intestinal motility disorders. Gastroenterology and Hepatology, Volume 15, May 2018. 

v. Jurisdictions JJ, JM and MolDx, Palmetto GBA, July 2020; Billing & Reimbursement – 13C-Spirulina GEBT. Accessed June 24, 2021.