Cathartics, Charcoal, Child, Preschool, Citrates, Citric Acid, Defecation, Double-Blind Method, Feces, Follow-Up Studies, Gastrointestinal Motility, Humans, Infant, Magnesium Sulfate, Poisoning, Prospective Studies, Sorbitol, Sorption Detoxification, Time Factors, Treatment Outcome, Vomiting