Symptoms of a pelvic inflammatory disease & what's the cause? Need info?

Infertility & pain. No symptoms in 10%. Pelvic pain, tender cervix, vaginal discharge, usually mal-odorous, irregular menses, pain with sex, bowel movements & full bladder. Causes most commonly std such as gonorrhea, chlamydia or trichomonas from having unprotected sex with an infected partner. Can be caused by an iud, or following an abortion or misscarriage, blood or lymph born infection.