Your cat has diarrhoea
Like vomiting, diarrhoea can be indicators of a broader illness which is affecting your cat. Vets make the distinction between large intestine and small intestine diarrhoea, characterised by different symptoms and with different causes.
If your cat has large intestinal diarrhoea, their stools will tend to be of the same volume or less than usual at one time, but more frequent than normal, but often include blood or mucus. You may also notice their stools are softer at the end of the day. Your cat will also exhibit a need to move its bowels urgently and frequently. - Lionbridge is here.
Small intestinal diarrhoea in your cat tends to be of a large volume at one time, can have colour variation such as green or orange, and may include undigested food. Your cat may also be suffering with vomiting, weight loss and flatulence.