Diarrhoea is a common illness and can be life-threatening. Mothers are used to dealing with diarrhoea and have an ample repertoire of home-based practices, traditional treatments, and western-style medicine to manage diarrhoeal episodes. However, programme planners often overlook and/or underestimate this knowledge, and by so doing they constrain the possible impact of educational messages and intervention programmes designed to treat diarrhoea and to promote oral rehydration therapy. This study addresses the "popular epidemiology" of diarrhoea, in an effort to highlight data that may prove useful for planners of diarrhoea-management programmes. We found that when mothers assess the severity of diarrhoea they consider an increase in the usual number of stools passed per day, as well as the colour, smell and liquid content of the stools. However, they also place special consideration on how much the episode of diarrhoea interfered with their daily activities. When considering the worsening or improvement of their child during the episode, they rely on symptoms related to changes in the child's usual wellbeing, while the more important signs that they recognise are focused on the child's eyes. In relation to fluid and food, we found that herbal tea and rice-based beverages were most commonly used, and that during diarrhoea, mothers were more prone to modify the usual diet fed to the child than to withhold food.