The Four Phases of Cyclic Vomiting Syndrome

CVS has four phases:

• prodrome
  
  
• episode
  
  
• recovery
  
  
• symptom-free interval
  
  

The prodrome phase signals that an episode of nausea and vomiting is about to begin. This phase, which is often marked by abdominal pain, can last from just a few minutes to several hours. Sometimes taking medicine early in the prodrome phase can stop an episode in progress. However, sometimes there is no warning: A person may simply wake up in the morning and begin vomiting.

The episode phase consists of nausea and vomiting; inability to eat, drink, or take medicines without vomiting; paleness; drowsiness; and exhaustion.

The recovery phase begins when the nausea and vomiting stop. Healthy color, appetite, and energy return.

The symptom-free interval phase is the period between episodes when no symptoms are present.

source: http://digestive.niddk.nih.gov/ddiseases/pubs/cvs/index.htm