Five hundred million attacks of diarrhoea occur each year in children under 5 years of age, throughout the world, and acute gastroenteritis remains a frequent cause of admission to hospital in the United Kingdom. Current practice in the treatment of diarrhoeal dehydration in the UK is focused upon intravenous rehydration. Drugs (eg antibiotics, anti-emetics, anti-diarrhoeal agents and absorbents) are commonly prescribed, and ‘therapeutic’ starvation, followed by cautious reintroduction of diet, is recommended. Studies conducted by health workers in developing countries have challenged these dogma. Whilst intravenous rehydration is occasionally required (eg. in shock, ileus or coma) the majority of episodes of dehydration can be treated orally. Oral rehydration is less unpleasant than intravenous infusion, safer, quicker, cheaper and readily administered by parents with nursing supervision. Recovery may be hastened by continuing to breast feed and offer normal diet, and weight loss is minimized. These principles are being applied in pilot studies at The Children's Hospital, Birmingham. Outpatient treatment is largely supervized by trained paediatric nurses, after initial medical assessment of the child. Nurses are becoming more confident in the technique of oral rehydration, coupled with early reintroduction of food. This is reflected in less discomfort and weight loss for the child, less parental anxiety, decreased length of hospital stay, and financial savings.