Unable to recruit sufficient participants form parent study following protocol expansion

The purpose of this study is to compare a less invasive breath test against the current standard for assessing gastric (stomach) emptying. The current standard of care is a procedure called Nuclear Scintigraphy of a Solid Meal (NSSM). This study will compare this method to a Gastric Emptying Breath Test (GEBT).

Inclusion Criteria:

• Subjects must be 22-65 years of age at time of enrollment
• Subjects must already be consented to 17-007934 or 19-001254
• Subject must be agreeable and compliant with study requirements, including up to three (baseline, 2 month, and 6 month) visits, as well as undergoing GEBT and NSSM testing.
• If female, must be post-menopausal, surgically sterile, or agree to practice a form of birth control or abstinence during year of study and have negative serum HCG at screening/baseline
• Must be willing and able to travel, as needed, to the Investigator's office to complete all routine follow-up visits

Exclusion Criteria:

• Persons presently or soon to be incarcerated
• Females who are pregnant or suspect they may be pregnant
• Persons with nicotine and/or alcohol dependence
• Patients with cognitive impairment that limits their ability to make autonomous decisions
• Known allergies or sensitivities to study materials (eggs and spirulina)
• Assessed, by the physician or delegate, that enrollment would not be appropriate

Those eligible from relevant sub-studies.