1. 1 episode of nonbilious, nonbloody vomiting within the 4 hours preceding triage The requirement for only 1 vomiting episode is based on prior work which similarly required 1 vomiting episode within 4 hours of triage. The later study reported a 17% absolute reduction in the use of IV rehydration. The vast majority of children seeking care and enrolled in the aforementioned study had a significantly greater number of vomiting episodes in the preceding 24 hour (mean >9 episodes).