DefinitionPelvic inflammatory disease is a general term for infection of the uterus lining, fallopian tubes, or ovaries.See also: EndometritisAlternative NamesPID; Oophoritis; Salpingitis; Salpingo-oophoritis; Salpingo-peritonitisCauses, incidence, and risk factorsMost cases of pelvic inflammatory disease are caused by bacteria that move from the vagina or cervix into the uterus, fallopian tubes, ovaries, or pelvis.The most common cause of PID is sexual contact without using a condom or other protection. This is called a sexually transmitted disease (STD). Chlamydia and gonorrhea are the two bacteria that cause most cases of PID.However, bacteria may also enter the body during some surgical or office procedures, such as:ChildbirthEndometrial biopsyInsertion of an intrauterine device (IUD)M