Hi ! Good afternoon. I am Dr Shareef answering your query. With the history of infected IUD, and a miscarriage, and long term treatment for the PID (pelvic inflammatory disease), there is a possibility of your pelvic organs getting adhered either to each other or surrounding structures, and this adhesion might be responsible for the pain. Usually it is seen that in chronic PID is very difficult to eradicate completely, and the pain could radiate to the back and lower limbs. If I were your doctor, I would advise you for a urine routine and microscopic test followed by a culture and sensitivity test of both the urine and vaginal swab to be sure of the best possible antibiotic effective against the chronic infection. If you are sexually active, you have to take appropriate precautions so that you do not get or spread the infection on either side. An ultrasound of the abdomen would be helpful in such cases, and if need be a diagnostic laparoscopy might be advised by your gynaecologist in case of intractable pain disturbing your routine activity. I hope this information would help you in discussing with your family physician/treating doctor in further management of your problem. Please do not hesitate to ask in case of any further doubts. Thanks for choosing health care magic to clear doubts on your health problems. Wishing you an early recovery. Dr Shareef.