Currently, a new generation of high-resolution electrogastrograms recording technology with 64-channel electrode array is being developed by Alimetry Limited. This BSGM provide a more complete understanding of the origin and propagation of human gastric slow-wave activity non-invasively, such as frequency, amplitude, velocity, and pattern, in high spatiotemporal detail. The system is also capable of providing a novel meal response metric, which might correlate with the gastric emptying time. The system includes an App for tracking patient-reported symptoms throughout the test.The aim of the present study is to assess and compare BSGM and breath-based gastric emptying parameters and to study the relation between BSGM and presence or severity of individual symptoms and clinical features.The investigators will perform a study in 100 subjects to record gastric bioelectrical activity by non-invasive multi-channel body-surface electrode arrays during gastric emptying breathing test.

Inclusion Criteria:

• Aged >18 years old;
• Male or female patients;
• Patients planned GEBT;
• Negative PCR on nasopharyngeal swab 24 or 48 hours prior to the test;
• Signed informed consent.

Exclusion Criteria:

• Females who are pregnant or lactating.
• History of skin allergies or a history of extreme sensitivity to cosmetics or lotions
• Fragile skin vulnerable to skin tears.
• Damaged epigastric skin (open wounds, rash, inflammation)
• Patients unable to remain in a relaxed reclined position for the test duration

Subjects who will receive gastric emptying breath test