[1] Univ Calgary, Alberta Childrens Hosp, Res Inst, Cumming Sch Med,Sect Pediat Emergency Med, Calgary, AB, Canada
[2] Univ Calgary, Alberta Childrens Hosp, Res Inst, Cumming Sch Med,Sect Gastroenterol, Calgary, AB, Canada
[3] Univ Alberta, Dept Pediat, Alberta Res Ctr Hlth Evidence, Edmonton, AB, Canada
[4] Univ British Columbia, BC Childrens Hosp, Div Pediat Emergency Med, Vancouver, BC V5Z 1M9, Canada
[5] Dalhousie Univ, Dept Emergency Med, Emergency Dept, IWK Hlth Ctr, Halifax, NS, Canada
[6] Univ Montreal, Ctr Hosp Univ Ste Justine, Sect Pediat Emergency Med, Montreal, PQ, Canada