This is called a decidual cast. It occurs when the lining of a woman's uterus sheds as one massive solid piece of tissue during her period. : r/MakeMeSuffer

This came out of me..I'm scared **Graphic image warning**

We just learned this horrifying fact about periods, and we wish we

Uterine (decidual) Casts - Don't Forget the Bubbles

meowr_11 (u/meowrii_) - Reddit

Decidual cast: Definition, symptoms, causes, and more

Woman Goes Viral for Detailing Rare Experience of Decidual Cast

Decidual cast from a woman - Stock Image - C058/5454 - Science

Is this a decidual cast? Am I supposed to do anything about it

This Nurse's TikTok About Passing a Decidual Cast During Her

DaisyBaby4Twenty (u/DaisyBaby4Twenty) - Reddit