Weird Problem at the base of my spin by sphincter... Question Inside?!

Weird Problem at the base of my spin by sphincter... Question Inside?

So. This recently started maybe a week ago. I thought it was something that was caused how I slept or something.

Something is moving at the base of my spin. Whatever it is can be moved if I squeeze and release my sphincter or if I am sitting in a seat sway my hips left to right I can feel it move.

I don't feel sick. No fever. No headache no aches or pains.

What is this?!?!!?!?

2 weeks ago
It is inside the skin. Not on the outside.

Don't know if that changes the answer.

Sphincter says "What"?

BR