A magnetic resonance imaging scan clearly shows lesions in the ovaries, fallopian tubes, bladder, cervix, and uterine ligaments. The gynecologist suspects that the cause of P.N.’s pain is...

A magnetic resonance imaging scan clearly shows lesions in the ovaries, fallopian tubes, bladder, cervix, and uterine ligaments. The gynecologist suspects that the cause of P.N.’s pain is endometriosis. How might the gynecologist best confirm her diagnosis?