Shortly after sex last night, I noticed blood on the bed. It had come from the tip of my husband's penis. He said that it stung a little. What could have caused the blood? I have an IUD. Could it have been the strings from the IUD poked him?
The strings of the IUD could have poked him, but really hsouldn't make him bleed. They are like fishing line, and are pretty flexible.
Are you sure it wasn't from you? That seems more likely. If he has blood in his ejaculate when he masturbates or in his urine when he pees, he needs to see a doc, it could be an infection. But during sex, the blood just usually comes from the woman (it's so easy to scratch or irritate the vagina /cervix during sex)
If you're sure it was from him, he should get checked out.