Suggest Treatment To Stop Spotting And Cramping In Woman With IBS?

I have had my mirena iud for 4 months now. I have never been pregnant but my doctor and I decided mirena was the better choice due to my already heavy and long menstrual cycle. (Average 9 days). I am 32, white, never pregnant, married, obese, ibs or crohns (under care now), depo shot for 3 years previous to iud. (Would work for two months then spot and bleed the last full month before next shot). No history of cancer, ovarian issues, or other known concerns. The bleeding went down after two months but I continue to spit every day to every other day. I also have cramping that is painful and persistent. My spotting varies from clear mucus with blood to thicker light blood-colored discharge. I have not had a regular period while on the mirena. Is there anything that can be done to stop the spotting and cramping? The spitting is a annoying but the cramping is my main concern. It is inferring with my day to day life and causing me fatigue as well as lack of concentration.