If the black spots remain, you need to get this checked out, as blood can be black. You can have an occult blood test done which is very simple and you do it at home. Much depends on your age, if there is a family history of colon cancer, etc. Your BM's will change depending on what you eat and how much. You want to watch for change in color, pencil thin stools, bleeding and pain. I think what you are seeing are poppy seeds, and if this goes away, let it go. Unless you see some real symptoms, don't obcess over this. It all depends on your age, family history and symptoms. If the black spots disappear, I wouldn't worry. If you're nearing 50 it's time for a coloscopy anyway, and this would be a good time to get one. Take care.
I was diagnosed with colon cancer 3 months ago. All stool patterns can change with what you eat and the amount you eat. As for the poppy seeds still being in your system after 2 days yes it is possible. But not everyone has the same signs or symptoms if it would make you feel better contact your doctor and see what he or she recommends. Just because it seems small doesnt mean a problem doesnt exist or that it does. So talk to your doctor. Good Luck