Abstract
It has long been possible to isolate viruses from the stools by culture, though the viruses found are rarely implicated in disease of the gut. In contrast, only recently has it been possible to identify viruses in the stools of patients with diarrhoea. Initially, such identifications were made by electron microscopy but the unsuitability of the microscope for large-scale screening has led to the development of other methods. The new methods have concentrated on rotaviruses but other viruses are also implicated and an overall view of the significance of finding a virus in any stool specimen has to take into account the evidence about all viruses, old and new.