Quite literally, this is the term for shitattack. An undesirable state. It is when you feel as though the stool in your bowels has shot up and landed in your mouth due to an unwanted or unexpected surprise. And hilarity ensues for everyone else.
Arsalaan found out about the child he fathered 12 years ago during a one night stand because she showed up on his doorstep and dude had a full out Gwano Blitz right there in the foyer.