Has your friend with the IUD ever been pregnant? If not yeah there can be some pain, but she should probably see a doctor not wait it out. Nothings perfect.lisadagz said:and the IUD can be uncomfortable for women (my friend got one recently and says it feels like there are mini chainsaws in her uterus, she's going to stick it out for a bit and then get it removed if it's not calmed down) and also for men (my boyfriend's worried about me getting an IUD 'cause he's been with a girl who had one and apparently the strings stabbed him in the dick).
As for the strings I really doubt that. They're not a sharp material and they curl up. Not saying he's lying, rather that's what he believes and the explanation is probably something simpler (friction induced injury or something like that).
An IUD once comfortably settled really is a great option.
Permanent contraception (tubal) isn't without it's complications, it is a surgical procedure after all.