the coil is a small plastic T shaped device which is inserted into the uterus by the vagina.There are two types of coil IUD This releases hormones into your system and the copper coil which is non hormonal based.They work by preventing sperm from entering the uterus. and have two small strings which are used for removing the device.The device can last between 5-10 years and each month you check it's still in place by feeling for the strings (this is taught to you by the person fitting the coil).The coil should only be fitted by a fully trained doctor.The downside to the coil is that it can fall out, become disloadged and move into the wrong position making it less effective and it can also perforate the uterus and go into the intestines. There is a metal on it that makes it visible to x rays so if this does happen they can find where it is before removing it.The coil isn't suitable for everyone. There are different makes and sizes. You will have a small device put into your uterus this ensure that the right shape and size coil is fitted. Some doctors find that putting a coil into a woman who has had a baby in the past is easier because the cervix is tightly closed.Another downside to the coil, is that it can make periods more painful, longer and heavier than you are used to. This usually settles down are a couple of months, if not then the coil might not be suitable for you. Also, if you do get pregnant, then you risk it being eptopic (growing outside the uterus usually the fallopiean tubes). If you do find yourself pregnant, and it's inside the uterus, it's important to get the coil removed, this may cause you to miscarry (not you personally but its' a risk to all women who use the coil and get pregnant)Before the coil is fitted, you might be required to have some swabs taken. This is to make sure that you dont have any infections or STI's.The coil is not suitable for women who have unexplained vaginal bleeding or have Pelvic inflammatory disease (PID).There are other types of birth control which prevent against pregnancy, but the only one that prevents pregnancy and STI's is condoms.I would suggest you visit your doctor or local family planning clinic to talk through birth control, the types and which would be the best option for you.Hope this helpsI've had the coil fitted and I have to say it's not the most pleasant thing in the world. My dr had trouble fitting the coil and had the change the coil from 10 years to 5 years because the 5 year one is more flexible than the 10 year one. YOu have some cramping whilsst the coil is fitted which eases off. I've just got home and my stomache is killing me. I've got a hot water bottle on my tummy to see if that helps the cramping. I'll be on painkillers as well as using my hot water bottle.