Have chronic pid but at the moment treated by doctors words, went for barium enema due to pain in colon. they found nothing. what can be the cause?

2nd opinion/PID: You need to obtain a 2nd opinion from a GYN MD who has experience with Chronic Salpingitis (PID). Treating these cases are like trying to put out a dumpster fire, you think the infection(fire) is over with antibiotics (water) and it flares up again and again.

Treatment for PID: PID is a condition where a pathogen (sexually transmitted) goes up the cervix and uterus and through the fallopian tubes, into the pelvix, causing a more widespread infection. This is separate from your colon and if you're in severe pain, you will need antibiotic treatment, possibly a laparoscopic surgery if imaging shows an abscess. A barium enema would not be helpful for PID.