Diarrhoea can be caused by different routes. It is a diagnostic symptom of acute gastroenteritis.
Diagnostic criteria for acute gastroenteritis include "loose or liquid stools and/or an increase in evacuation frequency to three or more in 24 h". Acute diarrhoea lasting seven days or less, prolonged diarrhoea lasting eight to 13 days, and chronic or persistent diarrhoea lasting 14 days or longer (Guarino et al. 2018).