When standard tests look normal but symptoms continue, body surface gastric mapping may offer additional clues by measuring the stomach’s electrical activity alongside symptoms and gut-brain health. Developed by 47 experts from 13 countries, the Auckland Classification provides standardized criteria for interpreting and reporting these findings.
Greg O’Grady, Co-founder and CEO of Alimetry, and lead author of the consensus classification, discusses its potential relevance to gastric neuromuscular disease, its limitations, and the validation required before routine clinical adoption.
What clinical challenge led to the development of the Auckland Classification, and how does it improve the interpretation of body surface gastric mapping?
Around 1 in 10 people are affected by chronic gastroduodenal disorders worldwide, yet they remain difficult to diagnose and manage. Standard diagnostic approaches are often based on symptoms or nonspecific measures of gastrointestinal transit, such as gastric emptying time. These methods cannot always identify the underlying mechanism or help clinicians select the most appropriate therapy. This diagnostic gap prompted us to develop a more mechanistic approach to patient profiling.
Body surface gastric mapping (BSGM) measures the stomach’s electrical slow waves, which help initiate and coordinate peristalsis. The findings can be assessed alongside real-time symptoms and measures of gut-brain well-being, allowing researchers to examine possible mechanisms of dysfunction rather than only their downstream effects.
The Auckland Classification provides a structured, consensus-based research framework for interpreting BSGM findings. It defines patient phenotypes and establishes a common language for reporting and comparing results. Before its development, there was no standardized approach to determining the potential clinical meaning of these findings.
How does body surface gastric mapping add to existing diagnostic tools when assessing patients with gastroduodenal disorders?
BSGM is intended to complement existing tests rather than replace them. Endoscopy remains essential for identifying or excluding structural pathology, while gastric emptying studies assess transit time. BSGM provides information about the electrical activity coordinating gastric function, particularly in patients whose standard investigations are normal despite persistent symptoms.
Gastric emptying studies measure how quickly the stomach clears a meal, but they do not directly assess the electrical activity involved in that process or the sensory aspects of a patient’s condition. Evaluating electrophysiological findings alongside symptom and psychological assessments may provide a broader view of gastric function.
As a surgeon, I understand how difficult it can be to evaluate patients when existing tests do not identify a specific cause. Symptoms may be associated with neuromuscular dysfunction, visceral hypersensitivity, or altered gut-brain signaling, but standard investigations cannot always distinguish between these mechanisms. This challenge contributed to the development of the Auckland Classification.
How could a standardized classification improve diagnostic reporting and help clinicians make more consistent decisions?
Before the Auckland Classification, individual centers developed their own methods for classifying and reporting BSGM findings. These heterogeneous approaches made it difficult to compare results, conduct multicenter studies, or build the evidence required for clinical adoption.
A standardized classification gives clinicians and researchers shared terminology, phenotype labels, criteria, and an interpretation framework. This consistency supports comparisons between centers and the design of prospective trials. It may eventually help researchers determine whether specific phenotypes are associated with particular treatment responses.
Other areas of medicine have undergone a similar process. The Chicago Classification established a standardized approach to interpreting high-resolution manometry in esophageal motility disorders. The Auckland Classification may provide a comparable research foundation for gastric mapping.
What could this new framework mean for patients?
For patients, the main potential benefit is reducing prolonged diagnostic uncertainty. Many people with chronic gastroduodenal disorders consult several specialists and try multiple medications without receiving a clear explanation for their symptoms. In some cases, standard tests may not be sensitive to the underlying mechanisms.
The Auckland Classification provides a framework for interpreting objective, mechanism-based findings from BGSM. These findings can give clinicians a clearer starting point than transit measurements alone. For example, the test may identify patterns associated with altered gastric electrical or neuromuscular activity, sensory dysfunction, or gut-brain signaling.
The treatment implications remain research oriented, and additional data are needed before specific phenotypes can be used to guide therapy routinely. However, for patients who have spent years without an explanation for their symptoms, an objective characterization of their condition may be a useful step toward more focused clinical assessment.
What further validation is needed before the Auckland Classification can be adopted into routine clinical practice?
The framework was designated version 1.0 because further revisions are expected as the evidence develops.
An immediate priority is the prospective validation of relationships between phenotypes and treatment responses. Early data suggest that patients with the Low Meal Response phenotype may experience a better symptomatic response to prokinetic therapy. The Dysrhythmic phenotype may be associated with lower response rates to initial interventions and a greater need for escalation of care. These observations require confirmation in larger, prospective, multicenter cohorts before they can inform clinical guidelines.
A classification for adolescent patients is also in development. Another research priority is to clarify relationships between BSGM phenotypes and histopathological changes. One example is the possible association between depletion of interstitial cells of Cajal, a feature of gastric neuromuscular disorders, and gastric electrical dysrhythmia.
Version 1.0 should therefore be regarded as the starting point for a framework that can be refined as new evidence becomes available.
What are the main challenges to introducing body surface gastric mapping into everyday diagnostic pathways, including point-of-care settings?
Several practical challenges remain. The current standard protocol is a 4.5-hour supervised test conducted in a clinic or hospital, similar to gastric emptying testing. Alternative protocols are being investigated, and the testing process may change as further evidence becomes available.
Clinical utility, cost-effectiveness, and the effect on subsequent investigations and treatment decisions must be demonstrated prospectively. Reimbursement pathways and access will also influence adoption.
Training and interpretation require investment. Clinicians must understand what BSGM findings mean and how to incorporate them into existing diagnostic pathways. The Auckland Classification addresses part of this challenge by providing a standardized interpretation framework, but further education and implementation support are needed.
Looking ahead, how do you see this classification evolving, and what role could it play in the future of diagnosing and managing gastroduodenal disorders?
The classification applies lessons from cardiac electrophysiology and esophageal motility testing to gastric medicine. Its purpose is to support a shift from broad symptom-based labels toward a more objective, mechanism-based understanding of gastroduodenal disorders.
The framework will be revised as prospective validation studies are completed, evidence for individual phenotypes develops, and new findings emerge. Potential phenotypes that did not meet the evidence threshold for version 1.0 remain under investigation.
Artificial intelligence-assisted analysis may eventually make BSGM interpretation more consistent and scalable. As the evidence develops, the classification could also support therapeutic trial design by helping researchers examine relationships between phenotypes, disease mechanisms, and treatment responses.
The longer-term objective is to support more precise management of gastroduodenal disorders and assess whether similar classification approaches could be applied to colonic conditions.
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