Bacillus Particles Prevent Children Antibiotics Associated Diarrhea

This prospective, multicenter, randomized, double-blind, placebo-controlled clinical study, into the group of children in the hospital that use clinical antibiotics from one month to three years old，by observing the given antibiotics at the same time with the whole bowel raw or placebo, prevent the happening of the antibiotic associated diarrhea, evaluate the whole bowel prevention clinical efficacy and safety of AAD. Outcome measures 1. MAIN OUTCOME MEASURES: The incidence of diarrhea (stool frequency and character daily rates), the duration of diarrhea, the degree of diarrhea occur. 2. Secondary outcomes: intestinal flora and relevant metabolites, micro-environmental changes.