Shit a hole through the floor

To be so startled/terrified that you shit yourself in such a way that your excrement hits the floor and burns a solid hole directly through it.

Used to indicate that a situation is/was exceptionally horrifying.

Similar to shit bricks

When I saw the murderer's mask, I shit a hole through the floor and ran.

When shit hit the floor

As in Putin descending on his coccyx and soiling his pants

putin-reportedly-took-a-big-fall-as-speculation-over-worsening-health-grows. When shit hit the floor