This study assessed the clinical management and impact of diarrhoea aetiology (rotavirus positive/negative) and rotavirus genotype on diarrhoeal disease severity. Of 7391 diarrhoea admissions less than 5 years of age over a 2-year period, 80% of patients were tested for rotavirus, 87% were cultured for bacterial pathogens and 78% were assessed for both. Diarrhoeal severity scores were greatest in those children with mixed rotavirus and bacterial infections. Between 1.3 and 8.4% of infants were considered dehydrated yet intravenous fluids were used for 48% of infants (69% rotavirus positive, 72% mixed infection). These findings support the promotion of oral rehydration therapy over intravenous fluids.