Cyclical Vomiting Syndrome is a rare, unexplained disorder of children and some adults which was first described by Dr. Samuel Gee in 1882. The condition is characterised by recurrent, prolonged attacks of severe vomiting, nausea, and prostration, which occur for no apparent reason and without apparent cause.
Vomiting persists at frequent intervals for hours or days. The episodes are self limiting and tend to be similar to each other in symptoms and duration. Between episodes the child is in good health and is symptom free.
The most common age for onset of CVS is at 3-7 years, but it can occur from infancy to adulthood. The episodes may recur several times a month to several times a year. There is often a family history of migraine.
Episodes may start at any time but typically begin in the early morning or during the night. There is relentless nausea with repeated vomiting (5-6 times an hour at peak) and pallor. There may be intense thirst, headache, fever or abdominal pain.
Some episodes are completely random and unpredictable, others have an identifiable trigger such as infections, stress of any type, and anaesthetics.
Diagnosis is difficult because vomiting can be caused by a large number of disorders other than, and more common than, Cyclical Vomiting. Diagnosis is made by a careful review of the history, physical examination and tests to rule out other diseases that may cause vomiting.
Medication can sometimes be found to prevent, abort or shorten episodes. Early intervention, a dark, quiet environment and IV fluids used as needed.
The above description is from the Australian CVS Page.