The effect of gastric surgeries (anti-reflux or bariatric) on symptoms and gastric activity using Gastric Alimetry in patients indicated for gastric surgery

This is a prospective observational cohort study. The exposure is gastric surgery (anti-reflux or bariatric), undertaken as part of standard clinical care. The study will observe changes in gastric function and symptoms before and after surgery. Participants would not have routine clinical access to body surface gastric mapping (BSGM) outside of research; however, they may be able to undergo BSGM in other clinical studies run by Alimetry (longitudinal study). Access to BSGM is not limited solely to this study but is available through participation in approved research protocols. The Gastric Alimetry device is a non-invasive test applied to the upper abdomen (stomach region) using a flexible array containing 64 electrodes adhered to the skin. Participants recline comfortably during the ~4.5-hour test, which captures high-resolution gastric myoelectrical activity along with real-time symptom logging. (Refer to the attached protocol for full procedural details.) Procedures and activities include: Participants will undergo body surface gastric mapping (BSGM) using the Gastric Alimetry device. This is a non-invasive test lasting approximately 4.5 hours. The baseline BSGM will be performed 1–30 days prior to the planned surgery. Participants will complete validated questionnaires at baseline, 6 months, and 12 months. These include GCSI, PAGI-SYM, PAGI-QOL, EQ-5D, STAI-6, PHQ-8, GAD7, PSS4, and possibly the GCSI Daily Diary Symptom scale. BSGM will be repeated at 6 months post-surgery Medical records will be reviewed to confirm clinical history and surgery details. Delivery and personnel: The BSGM test and questionnaire administration will occur face-to-face and individually at the Macarthur Clinical School, Western Sydney University. Trained clinical research staff or medical students under supervision will conduct the assessments. Surgery will be performed independently by the treating surgical teams as per standard care at affiliated hospitals. For the purposes of this study, standard care is defined as the routine clinical management of patients undergoing gastric surgery (anti-reflux or bariatric) by their treating surgical teams. This includes the usual pre-operative assessment, the surgical procedure performed according to standard hospital protocols, and post-operative follow-up as determined by the treating clinician. The study is observational only and will not alter or influence the clinical care pathway or surgical decision-making. Duration of observation: Each participant will be followed for up to 12 months post-surgery.