In a prospective survey carried out over 12 months 447 children aged under 2 years were admitted to the Manchester Regional Infectious Diseases Unit for treatment of gastroenteritis. Comparison of the children with those in a survey 15 years previously in the same unit showed that the illness was milder than in the earlier series, with no deaths and with lower incidences of hypernatraemia (1%), uraemia (8%), and dehydration (14%). These improved findings occurred despite several deficiencies of care in the prehospital phase of the illness, particularly poor compliance with the widely recommended guidelines for fluid and dietary management in infantile gastroenteritis.