I had blood in my urine after my bag was removed. I had a sever bladder infection and they treated it with leviquin (if I'm spelling this wrong, I apologize)....several days later by bladder locked again, with the same infection. . They did another culture and the leviquin didn't work for that type of bacteria, They put me on another antibiodic. Long story short, in the end, I ended up on IV antibiodics for 2 days.....
I would get to your doctor right away and get another urine culture done, if you haven't already.
Jeff