i would suggest before you take the ciprofloxacin
you need to investigated to what is the problem,
you need to get a urine test done, an ultrasound
if you have an anal swelling then the blood you are noticing could be from hemoorhoids you might be suffering from.
if your a male then we need to rule out any problem with prostate
if you having blackish stool then we need to rule out ulcers as well.
if no anal swelling then we need to investigate if the bleeding is coming from the intestines due to ulcers or inflammation or mass that is bleeding
so would suggest you see a specialist to do a proper checkup and give treatment to the cause found.
hope to have answered your query
get well soon.