Cyclic vomiting syndrome is a disorder characterized by nausea and vomiting, separated by periods without any symptoms. There is very little research on this field at this point and most doctors do not fully understand the disorder. The goal of this study is to assess how the stomach empties food. Participants will be asked to participate in this study because either (a) they have been diagnosed and/or treated for cyclic vomiting syndrome in the past, or (b) they are physically healthy. The study seeks to compare how a healthy person's stomach empties to how the stomach of someone with cyclic vomiting disorder empties.

Up to 14% of unexplained vomiting in adults is attributed to an under recognized and often misdiagnosed disorder termed cyclic vomiting syndrome (CVS). As CVS is better understood, gastroenterologists are increasingly recognizing the importance of timely diagnosis and early management for this chronic and debilitating disorder. Currently, the only gold standard diagnostic strategy involves evaluating clinical criteria set by the Rome Foundation, such as vomiting frequency and duration of episodes. Outside of these subjective criteria, no definitive and objective diagnostic strategy for cyclic vomiting syndrome exists.

Developing diagnostic strategies has been difficult given the exact etiology of CVS is still unknown. One physiologic theory includes rapid gastric emptying (GE)-or a dumping-like syndrome related to impaired gastric accommodation. A retrospective analysis observed rapid gastric emptying by standard 4-hour scintigraphic gastric emptying study in 80% of subjects, suggesting a relationship with CVS and rapid GE. In turn, rapid emptying has been hypothesized to relate with abnormal gastric accommodation - the reflex allowing storage of food through increased fundic volume. This physiologic abnormality can be readily and easily measured using non-invasive tools, but have never been tested in CVS. To explore this further, we aim to determine if CVS patients have abnormal gastric accommodation measured by nutrient drink test.

Inclusion Criteria:

• Diagnosed with Cyclic Vomiting (or Healthy Volunteer)
• Age 18 or greater

Exclusion Criteria:

• Age Under 18
• History of gastric surgery
• History of marijuana use
• History of Gastroparesis
• History of Diabetes mellitus II
• Upper endoscopy with known obstructive gastric disease
• Current pregnancy or lactation
• Active inflammatory bowel disease (Crohn's disease, Ulcerative colitis)
• Severe renal disease (GFR <15/dialysis dependent)
• Active malignancy (diagnosed in last 5 years)
• Allergy/intolerance to liquid Ensure®

The study seeks to enroll adult patients diagnosed with Cyclic Vomiting Syndrome, as well as healthy controls