Gastric Neuromuscular Function in GERD

Bodysurface gastric mapping (BSGM) will be used to assess gastric neuromuscular function in healthy controls and patients with medical refractory gastroesophageal reflux disease (GERD).Participants will undergo BSGM for 4-hours in addition to high resolution manometry (HRM), pH-impedance monitoring, and gastric emptying breath test.

Healthy controlsInclusion Criteria:Aged 18-70 years oldBMI 18-35Able to understand written and spoken EnglishAble to provide written consentAble to understand risks and benefitsExclusion Criteria:Antacid use (e.g. PPI, H2RA or Gaviscon) within last 12-monthsActive use of other medications known to impact gastric motilityUpper GI symptoms including but not limited to heartburn, regurgitation, epigastric pain, nausea and bloatingSignificant medical conditionHistory of skin allergies or hypersensitivityActive abdominal wounds or abrasions, fragile skinCurrent pregnancyVulnerable group e.g. prisoners/cognitive impairment/institutionalised individualsRegular cannabis users (unable to abstain for 7-days)Opioid userUnable to use a tablet deviceGORD patientsInclusion CriteriaReferred for 24-hour pH-impedance monitoringAged 18-70 years oldBMI 18-35Able to understand written and spoken EnglishAble to provide written consentAble to understand risks and benefitsExclusion CriteriaSystemic or metabolic disorder known to cause gastric dysmotility other than diabetes (e.g. scleroderma, multiple sclerosis, hyperthyroidism).History of upper GI surgery or hiatal hernia (>5cm, paraesophageal, or 'large' on endoscopy report)Diabetic and on insulinProven mechanical bowel obstructionHistory of skin allergies or hypersensitivityActive abdominal wounds or abrasions, fragile skinCurrent pregnancyVulnerable group - prisoners/cognitive impairment/institutionalised individualsRegular cannabis users (unable to abstain for 7-days)Opioid userUnable to use a tablet device