Precipitants and aetiology of cyclic vomiting syndrome.

Thirty-two patients aged 2-22 y with cyclic vomiting syndrome (CVS), and 64 age- and gender-matched controls were assessed to determine the nature, severity, precipitants and associated features of attacks and the incidence of potential aetiological factors. The mean age of onset was 3.5 y. Patients experienced a mean of nine attacks per year, of average duration 2.4 d, and two-thirds missed more than 10 d of school per year. Patients were more likely to have migraine and co-ordination difficulties, a past history of forceps delivery and gastroesophageal reflux than controls. Compared with controls, subjects had a higher incidence of psychological symptoms (38% compared with 19%) and migraine (37% compared with 9%). CVS is a chronic, disabling condition and is a migraine variant, with attacks usually precipitated by stress and intercurrent infections.