I had diarrhea once a month for 6 mos before getting the Mirena. I had changed from ortho tri cyclen to ortho tri cyclen lo. The doctor told me that progesterone affects smooth muscle ie. stomach intestines, etc. and that the change in the doses of the pills was causing this.He said that Mirena would be best for me because it is not systemic. I now know this is not true and since I have had it out I also had an endoscopy. I lost 20 # in the first 5 weeks of removal and was diagnosed with IBS. I believe that my problems at this point are all related to the hormones and I definitely have gotten better, although I'm not yet how I used to be. I have written other posts that might go into more detail...