What do systematic reviews say?

Combined oral and intravenous vs oral or intravenous alone

Combined oral and intravenous leads to lower surgical wound infection: combined oral and iv versus oral alone compared with oral or intravenous alone (high certainty).

• Antimicrobial prophylaxis for colorectal surgery 2014 · Cochrane Headline outcomes only
  RR 0.52 [0.35, 0.76]
  9 studies · 1880 participants
  High