Predicting Outcomes of GPOEM Using Gastric Electrical Mapping

Gastric peroral endoscopic myotomy (GPOEM) is a minimally-invasive procedure that involves dividing the pylorus, to enhance gastric emptying in gastroparesis patients. This is a single-arm, multi-centre, prospective observational study to determine the clinical utility of Gastric Alimetry in predicting GPOEM treatment outcomes. The investigators further aim to develop a clinical decision rule to inform patient selection. Gastric Alimetry will be conducted \<1 month prior to GPOEM. All subjects will then be followed up for 12 months.

This protocol proposes no change to the clinical management of patients which is left to the discretion of the patients' primary clinical team. Patients as part of this study will undergo a baseline assessment via Gastric Alimetry, and concurrent symptom, quality of life, and health psychology questions. GPOEM will be performed as per standard site protocol, with data captured in RDCap. Patients will be followed up at 1-month, 3-month, 6-months, and 12-months using the myCap (REDCap) app. Participants and clinicians can opt-in for a repeat Gastric Alimetry test at 6 or 12 months following their GPOEM procedure.

Inclusion Criteria: * Aged 18 years or older * Indicated for GPOEM Exclusion Criteria: * Pregnant or breast-feeding * Inability to perform Gastric Alimetry test: history of severe skin allergies or sensitivity to cosmetics or lotions; chronically damaged or vulnerable epigastric skin (fragile skin, wounds, inflammation); patients unable to remain in a relaxed reclined position for the test duration.