@dribbles you are NOT going to wipe out your intestinal flora with a single 500 mg Cipro - no way.
The antibiotic is given to prevent bacteremia - a blood infection which is usually transient (if at all) after biopsy. However, transperineal biopsies have about a Zero chance of this since the bacteria laden rectum is avoided completely.
I had no antibiotic administered after my TP biopsy. The worst part was hurriedly ripping the Band Aid off my taint the next morning when I realized it was still there just before a BM…OUCH!!!
Phil