Uncomplicated (nonsevere) diverticulitis

Patients with uncomplicated diverticulitis (ie diverticulitis without perforation, peritonitis, sepsis, septic shock, or an abscess larger than 5 cm in diameter) may not require antibiotic therapy. Patients without immune compromise who have uncomplicated left-sided diverticulitis do not routinely require antibiotics. Several randomised controlled trials have demonstrated that antibiotic therapy is not beneficial to these patientsDaniels, 2017Dichman, 2022Isacson, 2019Jaung, 2021Mora-Lopez, 2021. Antibiotic therapy is appropriate for patients with any of the following features:

  • immune compromise
  • right-sided diverticulitis
  • failure to improve after 72 hours of conservative treatment (ie no antibiotic therapy).

If antibiotic therapy is indicated for uncomplicated diverticulitis in adults, use:

amoxicillin+clavulanate 875+125 mg orally, 12-hourly for 5 days1. For dosage adjustment in adults with kidney impairment, see amoxicillin+clavulanate oral dosage adjustment. amoxicillin + clavulanate amoxicillin+clavulanate amoxicillin+clavulanate

For adults who have had a nonsevere (immediate or delayed) hypersensitivity reaction to a penicillin2, use:

cefuroxime 500 mg orally, 12-hourly for 5 days. For dosage adjustment in adults with kidney impairment, see cefuroxime dosage adjustment cefuroxime cefuroxime cefuroxime

PLUS

metronidazole 400 mg orally, 12-hourly for 5 days. metronidazole metronidazole metronidazole

For adults who have had a severe (immediate or delayed)3 hypersensitivity reaction to a penicillin, use:

trimethoprim+sulfamethoxazole 160+800 mg orally, 12-hourly for 5 days. For dosage adjustment in adults with kidney impairment, see trimethoprim+sulfamethoxazole dosage adjustment trimethoprim + sulfamethoxazole trimethoprim+sulfamethoxazole trimethoprim+sulfamethoxazole

PLUS

metronidazole 400 mg orally, 12-hourly for 5 days. metronidazole metronidazole metronidazole

Screening for colorectal cancer is recommended 6 to 8 weeks after an acute episode of diverticulitis for some patients with uncomplicated diverticulitis – see Colorectal cancer screening in patients with diverticular disease after an acute diverticulitis episode.

1 For patients with complicated (severe) diverticulitis switching to oral amoxicillin+clavulanate after intravenous therapy, consider giving amoxicillin+clavulanate 8-hourly if surgery has not been performed.Return
2 For patients with severe immediate penicillin hypersensitivity who tolerated initial intravenous therapy with ceftriaxone, it is safe to use cefuroxime.Return
3 Severe immediate hypersensitivity reactions include anaphylaxis, compromised airway, airway angioedema, hypotension and collapse. Severe delayed hypersensitivity reactions include cutaneous adverse drug reactions (eg drug rash with eosinophilia and systemic symptoms [DRESS], Stevens–Johnson syndrome/toxic epidermal necrolysis [SJS/TEN], severe blistering or desquamative rash), and significant internal organ involvement (eg acute interstitial nephritis).Return