Unfortunately, the only way to surefire diagnose endometriosis is through a laparoscopic surgery. Part of a lesion will be sent to pathology, and then it is either confirmed to be endometriosis or not. However, a surgeon will likely know if it’s endometriosis in the OR before it’s even sent to pathology.
The tricky thing about endometriosis is the extent of the disease does not correlate with symptoms/pain. This means a woman might have severe pain, but only have stage 1 disease. This also means a woman might have no pain at all, but might have stage 4 disease. This is why endometriosis is so commonly diagnosed when women are trying to conceive. It is common for a woman to have minimal symptoms, and then she cannot conceive and ends up being diagnosed with stage 4. Stage 4 endometriosis is pretty much when disease affects fertility.
I encourage all women to get a diagnosis one way or another (because you deserve to know what’s going on regardless of what the disease ends up being). If my disease had been diagnosed when I was much younger, I probably would have never had ovarian torsion and probably wouldn’t have needed a hysterectomy.