• Generally considered to be uncomplicated acute diverticulitis. See definition of complicated acute diverticulitis below under SEVERE.
  • Typically managed on an ambulatory basis with oral therapy.
  • The decision to manage on an outpatient basis depends on several factors including the severity of presentation, the ability to tolerate oral intake, and the presence of comorbid diseases.
  • Duration directed by clinical response.

Usual Pathogens
Enterococcus spp. (not routinely covered for mild-moderate infections)

Recommended Empiric Therapy (4 – 7 days)

Amoxicillin-Clavulanate 500 mg PO TID
TMP/SMX 1 DS tab PO BID + Metronidazole 500 mg PO BID
Ciprofloxacin 500 mg PO BID + Metronidazole 500 mg PO BID

IV Regimen (if initially unable to take orally)

Ceftriaxone 1 g IV q24h plus/minus Metronidazole 500 mg IV q8h
Switch to one of the above oral regimens when able to tolerate.

Severe pen-allergy or cephalosporin allergy (e.g. anaphylaxis, angioedemia):

Ciprofloxacin 400 mg IV / 500 mg PO q12h + Metronidazole 500 mg IV/PO q8h


  • Requires hospitalization.
  • Complicated diverticulitis (i.e. patients with perforation, obstruction, an abscess, or fistula).
  • Uncomplicated diverticulitis in the frail elderly, immunosuppressed, those with significant comorbidities, and those with high fever or significant leukocytosis.
  • Duration directed by clinical response.

Recommended Empiric Therapy (7 – 10 days)

Piperacillin-tazobactam 3.375 g IV q6h

Penicillin allergic (clear history)

Ciprofloxacin 400 mg IV q12h + Metronidazole 500 mg IV q8h + Vancomycin 15 mg/kg (round to nearest 250 mg) IV q12h.
Adjust vancomycin interval based on GFR.