To evaluate diagnostic accuracy of ultrasound for the presence of deep endometriosis.

The primary objective is to assess the diagnostic value of the ultrasound features in the diagnosis of deep endometriosis. The endpoints are the univariable diagnostic accuracies of ultrasound features (defined by the IDEA consensus statement) for the presence of deep endometriosis at any location: anterior compartment (i.e. bladder and its specific location) or posterior compartment (i.e. rectovaginal septum, uterosacral ligaments, torus uterinus, vaginal fornix and bowel involvement). All recruited patients are included in this analysis. The reference standard for this objective is whether there is deep endometriosis (at any location) or not (binary outcome).