A doctor will often suspect cyclic vomiting syndrome in adults when all of the following are present:

• Three or more separate episodes in the past year and two episodes in the past 6 months, happening at least 1 week apart
• Episodes that are usually similar to previous ones, meaning that episodes tend to start at the same time of day and last the same length of time—less than 1 week
• No nausea or vomiting between episodes, but other, milder symptoms can be present between episodes
• No metabolic, gastrointestinal, central nervous system, structural, or biochemical disorders.

Click here to learn more on how CVS is diagnosed:

https://www.niddk.nih.gov/health-information/digestive-diseases/cyclic-vomiting-syndrome/diagnosis