Suggest Treatment For Pelvic Inflammatory Disease

I went to the ER with abdominal pain and issues peeing. I very had pain off and on for 4 months until I finally had an attack that was so painful I couldn t take it anymore. ER test revealed no infection, or pregnancy in my urine. No positive STD tests. Trans vaginal ultrasound clean and no cysts. Pelvic exam revealed some discharge, and when pokI ng my uterus I could hardly stand it. Was told I have Pelvic Inflammatory Disease because I was inflammed and they needed to call it something. I also had increased white blood cells I believe from my urine test. Was given an antibotic and pain meds and told to follow up with a gyno. I very been nauseousness, and sometimes I notice what looks like a couple of small white rice shaped things when I pee. Pain is in the middle of my abdomein, where a csection scar it. Peeing hurts, bowel movements have been fine so far. Any idea what could have my uterus so inflammed?