It is important to recognize that, for practical purposes, all watery diarrhoeas can result in dehydration and can be treated in the same way regardless of their cause. Some cases of diarrhoea, however, have special therapeutic needs and thus a number of diagnostic procedures are required, which are listed here. If blood, or excessive mucus, is present in the stool, a stool culture should when possible be done to rule out shigellosis, and the stool examined microscopically to exclude amoebiasis. A stool culture is also indicated if there is a possibility that the case may be cholera. When any of these three conditions is suspected, antimicrobial drugs should be given. One must also consider whether the diarrhoea is caused by malaria or associated with measles, pneumonia, or otitis media, as some of these require specific therapy. Finally, one needs to be alert to the surgical conditions that may be associated with diarrhoea.