Simple clinical score and laboratory-based method to predict bacterial etiology of acute diarrhea in childhood.

We describe a two-step predictive method to assess the probability of bacterial etiology in cases of diarrhea. The patients are divided into three probability groups (high, intermediate, low) according to a clinical score. Thereafter the patients in the intermediate group are further assigned to the high or low probability group according to the presence or absence of fecal leukocytes. We developed the method in an initial series of 157 children with acute diarrhea; the reproducibility of the method was tested in a second series of 180 cases. Eighty-six percent of patients in the first series and 81% in the second were correctly classified by our method. We suggest its use, especially in pediatric practice, to identify children with the highest probability of bacterial diarrhea, thus reserving stool culture to a few selected cases because only a minority of children with diarrhea have a recognized bacterial etiology.