What is it

First thing to do is to read the leaflet that comes with your pills and read about the side effects. Would you say that the blood is actually in your excretion or urine? If so (either one) then you need to see your GP because often this can be a sign of a serious illness. Are you getting episodic abdominal pain with it? This again would suggest serious illness. You really need to see a doctor. It’s probably nothing to worry about but it’s possible it could be something like a parasite or cancer, you just need to make sure to be on the safe side. Hope this helps and I don’t make you worry too much x