Gastroparesis is a chronic and debilitating gastric disease associated with poor quality of life, psychological distress, frequent hospitalisations, and high healthcare utilization and associated costs. It is defined by persistent upper gastrointestinal symptoms and delayed gastric emptying with no mechanical gastric outlet obstruction. Gastric emptying scintigraphy (GES) is the current gold standard for diagnosing gastroparesis but its clinical utility is currently being questioned. Current management strategies have often been found to be ineffective, largely due to an incomplete understanding of the disease's pathophysiology. There is a critical need for more advanced diagnostic testing that can better diagnose patients and guide personalized targeted therapy.

Body surface gastric mapping (BSGM) using Gastric Alimetry (Alimetry Ltd., New Zealand) is a new FDA-cleared medical device to assess gastric function by non-invasively assessing gastric motility using simultaneous high-resolution electrogastrography and symptom profiling. BSGM has demonstrated clinical utility in the assessment of gastric function through patient phenotyping in a variety of cohorts, including patients with nausea and vomiting disorders, diabetes, delayed gastric emptying, and post-gastric surgery. Previous research revealed that the detection of gastric motility abnormality rates through patient phenotyping were higher using Gastric Alimetry compared to GES (43% vs 23%). Clinical application of these phenotypes has also aided in changing management decisions, which reduced healthcare utilization and associated costs. However, how GES and BSGM test results differentially influence clinical management in patients is uncertain.

This exploratory pilot study proposes a two-arm, prospective trial to assess whether BSGM-guided care could change clinical outcomes compared to the standard of care (GES) in patients with suspected gastroparesis. The trial consists of two phases. Phase 1 involves participants separately undertaking a GES and BSGM test. Based on these results, the referring clinician will devise management plans for treatment using a standardized form: 1) unblinded to one test (GES or BSGM) but blinded to the other test; and 2) unblinded to both tests (GES + BSGM). They will be asked to recommend any changes to interventions (medications, diet, endoscopic/surgical referral or other) and additional testing. In phase 2, those in Phase 1 will undergo BSGM-guided care based on their combined management plan (GES + BSGM) and followed up over a 12 month period. A separate set of participants will be recruited to undergo standard of care (GES only) in parallel with Phase 1 participants. After 12 months, those on the standard of care arm will be crossed over to BSGM-guided care, undergo a BSGM test, treated according to the new management plan, and followed up over 6 months. Questionnaires will assess symptoms, quality of life, health psychology, sleep, and work impact.

If validated, this may change clinical practice by reducing the need for invasive or radioactive-based procedures to diagnose these patients and facilitating a more targeted treatment approach.

Inclusion Criteria:

• Aged over 18 years old
• Meeting Rome IV Criteria for Functional Dyspepsia and/or Chronic Nausea and Vomiting Syndrome
• Referred for gastric emptying scintigraphy
• Normal gastroscopy
• Negative or treated H. Pylori status

Exclusion Criteria:

• Pregnant or breast-feeding
• Inability to perform a BSGM test according to Indications for Use: history of severe skin allergies or sensitivity to cosmetics or lotions; chronically damaged or vulnerable epigastric skin (fragile skin, wounds, inflammation); unable to remain in a relaxed reclined position for the test duration.