Cyclic vomiting syndrome (CVS), first described in children by Samuel Gee in 1882, is a chronic functional disorder of unknown etiology that is characterised by paroxysmal, recurrent episodes of vomiting.
The pathophysiology is unknown, but data suggest a strong genetic component in children with CVS, with evidence of mitochondrial heteroplasmies that predispose to CVS and other related disorders (eg, migraine and chronic fatigue syndrome). Other theories include autonomic dysfunction and, possibly, corticotropin-releasing factor (CRF) because stress is known to be a trigger for these episodes. The possible role of cannabis in causing CVS has been examined, though it remains controversial.
CVS is characterised by recurrent, discrete, stereotypical episodes of rapid-fire vomiting between varying periods of normal health. This on-and-off stereotypical pattern of vomiting is nearly pathognomonic.
