Duration of therapy dependent on clinical picture:

Peri-operative therapy ≤ 24h:

Bowel injuries due to penetrating, blunt, or iatrogenic trauma with surgery within 12 hours of injury; acute perforations of stomach, duodenum, and proximal jejunum in absence of antacid therapy or malignancy with surgery within 24 hours; or acute appendicitis without perforation, abscess, or peritonitis, and ischemic, non-perforated bowel.

Adequate source control - 2 days post-op with laparoscopic; 4 days with open surgical approach; 7 days if bacteremic

Source control delayed or not performed – 5-7 days:

- Monitor the following to determine if antimicrobial therapy can be discontinued sooner:

• temperature
• WBC/differential
• return of GI function

- Persistent clinical evidence of infection after 5-7 days warrants diagnostic investigations (CT, US).