Diarrhoea is defined by an increase in the frequency and/or volume of stool. Stools are soft or liquid.
If you cat lives indoors and has a litter, it is significantly easier to notice digestive disturbances. However, this is more difficult if your cats relieves himself outside. If he asks you to go outdoors more often, or its hair is soiled, your cat may have diarrhoea.
Even if diarrhoea can be quite frequent, it is not necessarily harmless. It is important to quickly identify and manage it.
It may have different origins : from poorly adapted food, internal parasites or ongestion of toxins. This is why diarrhoea must always be monitored.