Backache and pain lower abdomen are common complaints after copper iud insertion because it causes slight inflammation of the uterus. You can use analgesics like ibuprofen for the same. But if its very severe , you should meet up ur doctor. Problems with copper iuds like pain, backache, heavy bleeding are usually felt for first few months after insertion. Generally in 3months most patients get used to it. To rule out infection, you should see up your gynecolgist personally who will advise you medicine as per the nature of your discharge or after appropriate swab test and also examine the copper iud thread. As a copper iud user, you should feel for you thread (coil) after every menses. See a doctor immediately if you have severe pain abdomen, fever, dirty discharge, miss periods.