I have been using the IUD for about a year now. I know one of the side effects is spotting, but lately I have had light bleeding -- not just spotting -- about halfway through my cycle. It is like I am beginning my period. This has been happening for the past three months. I'm not sure if it is just a side effect of the IUD or if it is a sign of another problem. I never feel pain or cramping, just annoyance.

Karen

The IUD, being a foreign body in the uterus, can irritate the uterine lining and cause spotting. This is very common for a few months after an IUD is inserted. An infection associated with the IUD can do the same thing. Other, non-IUD-related causes of midcycle bleeding include endometriosis, fibroids or ovarian cysts.
If spotting or bleeding is new, beginning several months or longer after the IUD was inserted -- as in your case -- it should be investigated. Your gynecologist can examine you and do cultures to detect an infection. If infection is present, most of the time it can be treated without removing the IUD. If there is no infection, examination and/or ultrasound may be done to look for fibroids or cysts, which would then be treated as appropriate.