Inclusion Criteria:

• Male or female patients aged 18 years and older undergoing a clinically indicated gastric emptying study, with or without an assessment of small intestinal and colonic transit.
• Symptoms of dyspepsia (i.e., early satiety, postprandial discomfort, nausea, vomiting, regurgitation).
• Able to provide written informed consent before participating in the study.
• Able to communicate adequately with the investigator and to comply with the requirements for the entire study.

Exclusion Criteria:

• Clinical evidence of significant cardiovascular, respiratory, renal, hepatic, gastrointestinal, hematological, neurological, psychiatric or other disease that may interfere with the objectives of the study.
• Medications. Opiates, metoclopramide, and high doses of anticholinergic agents (e.g., amitriptyline greater than 50 mg daily).
• Treatment with GLP-1 agonists and amlyin which cause vagal blockade and may affect central processing of pain.
• Any other condition or prior therapy that, in the opinion of the investigator, would make the patient unsuitable for the study.