OBJECTIVES:To evaluate the role of routine stool examination for all pathogens in paediatric nosocomial diarrhea (NAD) and community-acquired diarrhea (CAD) over a two-year period at Alberta Children's Hospital and current practices in other Canadian hospitals. A secondary objective was to characterize features that may predict NAD or CAD etiology. STUDY DESIGN: Retrospective cohort study and telephone survey. SETTING: Alberta Children's Hospital (retrospective review) and Canadian tertiary care paediatric centres (telephone survey). METHODS:The health and microbiological records of all children with an admission or discharge diagnosis of diarrhea were reviewed using a standardized data collection form. In addition, a telephone survey of laboratories serving all paediatric hospitals in Canada was conducted using a standard questionnaire to obtain information about practices for screening for pathogens related to NAD. RESULTS: Four hundred and thirty-four CAD episodes and 89 NAD episodes were identified. Overall, rotavirus and Clostridium difficile were the most commonly identified pathogens. Bacterial culture was positive in 10.6% CAD episodes tested, with Escherichia coli O157:H7 identified as the most common non-C difficile organism. In NAD, no bacteria were identified other than C difficile (toxin). Screening for ova and parasites had negligible yield. Viruses were more frequent in the winter months, while bacterial pathogens were more common in the summer and fall months. Over 50% of Canadian paediatric hospitals still routinely process NAD specimens similarly to CAD specimens. CONCLUSIONS: There is a need for the re-evaluation of routine ova and parasite screening, and bacterial culture in nonoutbreak episodes of NAD in children.