Description for Gill :Kaogel is an off white oral suspension, containing 0.99 g Kaolin Light per 5 ml, for the treatment of diarrhoea of non-specific origins in cats and dogs. The active principal is kaolin light which is a well-established gastro-intestinal adsorbent of toxins and other substances. It also increases the bulk of the faeces to aid peristalsis.
I don't think I'd treat a cat with this myself without seeing the vet first in case it was the wrong thing to give for my cat's illness. I have never been prescribed this for a cat personally though I have had it for dogs alongside other meds for diarrhoea.