I had a chocolate cyst removed about 8-9 years ago.

I didnot have any endometriosis symptoms. But that cyst was caused by endo. No pain for me. Everythign was normal.

It's genetic- my mum had BAD endo. Like cannot get out of bed, heavy periods, MC for 3-5 days kind. She had a full hystrectomy and only that seemed to help.

Endo can return. It sucks, because the cause is ovulation. The endometrium lining grows somewhere else other than the uterine wall, and that is what causes the heavy bleeding and pain.