1.6.1.1 Cyclic vomiting syndrome

A 34-year-old primary school teacher reports five such episodes to date, each following an identical pattern that recurs at fairly predictable intervals. She describes recurring vomiting episodes: during the worst attacks she has been vomiting roughly four times an hour, and a full week or more clear separates one episode from the next. The most recent attack ran on for just over five days before finally settling. Between attacks she feels entirely well again, with no lingering nausea or discomfort. Onset is sudden and there is no headache preceding the episodes. She denies fever, abdominal pain, or diarrhoea, and her weight has remained stable. She reports that extensive investigation to date has not turned up any other explanation for the pattern.