When you're running up the stairs and it softly coats your hairs - Diarrhoea
When you're sitting in a tree and it trickles down your knee - Diarrhoea
When it comes out of your bum like a bullet from a gun - Diarrhoea
When you think you're friends are joking but your pants are warm and soaking - Diarrhoea

Or from personal experience:
When standing near the barbeque, the brown tide hits your shoe - Diarrhoea

MORE PLEASE.