What is the treatment for diverticulitis (inflammation of the diverticula)?

From the Guidelines

Antibiotic treatment is only advised in patients with uncomplicated diverticulitis who have comorbidities, are frail, present with refractory symptoms or vomiting, or have a CRP >140 mg/L or baseline white blood cell count > 15 × 10^9 cells per liter, while all patients with complicated diverticulitis should receive antibiotics. When considering treatment for diverticulitis, it's essential to assess the severity and presence of complications. According to the AGA clinical practice update on medical management of colonic diverticulitis 1, guidelines recommend antibiotics be used selectively, rather than routinely, in patients with acute uncomplicated diverticulitis. Some key points to consider in the treatment of diverticulitis include:

• The risk of progression to complicated diverticulitis is 5% among patients with acute uncomplicated diverticulitis, with risk factors including baseline ASA score III or IV, duration of symptoms longer than 5 days prior to presentation, presence of vomiting, CRP >140 mg/L, and baseline white blood cell count > 15 × 10^9 cells per liter 1.
• Patients who are immunocompromised are high risk for complications and should be treated with antibiotics, as well as those with evidence of systemic inflammation, abscess, perforation, or obstruction 1.
• When antibiotic treatment is necessary, the regimen usually includes broad spectrum agents with gram-negative and anaerobic coverage, such as a combination of an oral fluoroquinolone and metronidazole or monotherapy with oral amoxicillin-clavulanate 1.
• The duration of treatment is usually 4–7 days but can be longer, depending on general health status, immune status, severity of presentation, CT findings, and patient expectations 1.

From the Research

Treatment Options for Diverticulitis

• Outpatient treatment is recommended for afebrile, clinically stable patients with uncomplicated diverticulitis 2
• For patients with uncomplicated diverticulitis, antibiotics have no proven benefit in reducing the duration of the disease or preventing recurrence, and should only be used selectively 2, 3, 4
• Non-operative management, including bowel rest and intravenous antibiotics, is indicated for small abscesses, while larger abscesses should be drained percutaneously 2
• Surgical intervention is indicated for peritonitis or in failure of non-operative management 2

Antibiotic Treatment

• The use of antibiotics for uncomplicated diverticulitis is uncertain, with some studies suggesting no difference in outcomes between antibiotic and no antibiotic treatment 3, 4
• A systematic review found that the effect of antibiotics on complications, emergency surgery, recurrence, and long-term complications is uncertain, with low-quality evidence 3
• A study comparing ceftriaxone and metronidazole to piperacillin/tazobactam for complicated diverticulitis found no significant differences in outcomes, suggesting that ceftriaxone and metronidazole may be a suitable alternative 5
• Another study found that amoxicillin-clavulanate may be a suitable alternative to metronidazole-with-fluoroquinolone for outpatient diverticulitis, with no differences in diverticulitis-specific outcomes and a lower risk of fluoroquinolone-related harms 6

Diagnosis and Classification

• Radiological evidence of inflammation, using computed tomography (CT), is needed to diagnose the first occurrence of diverticulitis 2
• Diverticulitis is classified as complicated or uncomplicated based on CT scan, severity of symptoms, and patient history, which directs management 2
• Colonoscopy is recommended for all patients with complicated diverticulitis 6 weeks after CT diagnosis of inflammation, and for patients with uncomplicated diverticulitis who have suspicious features on CT scan or who otherwise meet national bowel cancer screening criteria 2