How long do cyclic vomiting episodes last, and can symptoms occur between episodes?

Details

Data on the natural history and symptom patterns of cyclic vomiting syndrome (CVS) are limited. CVS is a disorder of gut-brain interaction characterized by recurrent, stereotypical episodes of vomiting, retching, and nausea.

This 6-month, prospective, remote observational study assessed symptom patterns in adults with CVS using an electronic daily diary. Patients recorded their disease experience, including CVS symptoms and their severity, each day.

An episode started on the first day with 5 or more vomiting and/or retching (V + R) events. Episode end was defined as the first day of a run of at least 7 days without any diary-recorded V + R events in the prespecified main analysis, or at least 4 such days in the sensitivity analysis.

Of 93 enrolled patients, 88 (94.6%) recorded daily diary data during the study; these patients included 62 women and had a mean age of 37.7 years. Among those with diary data, 61 (69.3%) had at least one episode.

The prespecified main analysis identified 191 episodes, with a median of 0.6 episodes per 30 diary days and a median duration of 3.0 days. Of these episodes, 17.8% lasted more than 10 days. The sensitivity analysis identified 248 episodes, with a median of 0.7 episodes per 30 diary days and a median duration of 2.0 days.

Thirteen of the 88 patients with diary data (14.8%) reported vomiting or retching between episodes: these events did not meet the threshold for a study-defined episode. Other CVS-related symptoms apart from vomiting and retching—most frequently nausea, abdominal pain, and sweating—were reported more frequently during episodes than between episodes.

This prospective longitudinal study found marked variation in CVS episodes and highlighted the need to better define and characterize episodes in these patients.