Screening for enteric pathogens in stool samples from 249 children under the age of 36 months, admitted to hospital for non-gastrointestinal disorders, was positive at admission in 41 (16.4 per cent) in a prospective study of enteric pathogen acquisition and diarrhoea in hospitalized children. Infection with multiple organisms was found in 31/41 (75.6 per cent) children who were positive when screened at admission. Of 194 children who had no enteric pathogens on admission and could be followed up for 3 days after discharge, clinical or laboratory data showed nosocomial enteric infections in 39 (20.1 per cent). Presumed nosocomial infection with more than one organism was seen in only two patients and no pathogens were isolated in 14 (35.8 per cent). Children presenting to hospital may asymptomatically carry enteric pathogens and potentially act as a source of nosocomial infections. One in five children admitted into hospital without an enteric infection is at risk of developing a nosocomial gastrointestinal infection, with rotavirus being the most common aetiological agent.