['The number of admissions for acute gastroenteritis (GE) is increasing. The majority of patients pass through a single high-flow emergency department (ED) area which increases the risk of spreading GE. The aim of this study was to determine the frequency and aetiology of GE for acutely admitted patients and to analyse their clinical information focusing on risk indicators of contagious aetiology and on the chosen isolation regime to determine if the GE required a contact precaution isolation regime.', 'This study included patients above 16 years of age who were admitted acutely within a one-year study period to a Danish hospital with a catchment population of 231,000 persons. The following items were analysed: information from the referring doctor, diarrhoea, nausea and vomiting and fever history, abdominal pain, prior antibiotics, co-morbidity, drugs, travel history, contagious contacts, general condition, vital values, isolation regime, final diagnosis and results of stool examination.', 'Among 17,531 acute admissions, 1.6% had acute GE and 60% of these had stool examinations performed. Only 35% of the patients with GE had information about possible GE at referral. Short duration and vomiting may help to identify norovirus and antibiotic treatment within the last month to identify Clostridium difficile infections. All patients with highly infective GE were isolated under a contact precaution regime, but only one in four of the isolated patients were actually highly contagious.'] Is clinical information on admission insufficient to determine the appropriate isolation regimen for acute gastroenteritis?