A gynaecologic examination, including an ultrasound examination, will be performed by a gynaecologist at baseline. Provoked pain by a gentle pressure on the following 13 predetermined intra-pelvic anatomical landmarks will be assessed via vaginal palpation: the coccyx, the lateral part of sacrum at the insertion of the sacrospinous ligament, the middle part of the sacrospinous ligament, the insertion of the sacrospinous ligament at the ischiadic spine, the ischium inferior to the ilio-ischial fusion and the lateral and medial part of the pubic bone. All the structures will be examined bilaterally except for the coccyx.