Uncomplicated diverticulitis does not improve with antibiotics

Although acute diverticulitis is typically treated with a course of antibiotics, a randomized controlled trial just published in the journal Evidence Based Medicine examines this practice and finds that uncomplicated diverticulitis is not improved by antibiotic therapy. The authors state:

"Diverticular disease affects one in three people over the age of 60 years in Western countries and up to a quarter of these patients will develop diverticulitis. Acute uncomplicated diverticulitis typically presents with localised abdominal pain, fever and raised inflammatory markers. The current standard of care is antibiotic treatment, although evidence supporting this recommendation is lacking. This study evaluates whether or not antibiotic therapy for acute uncomplicated left-sided diverticulitis improves recovery."

They conducted a multicenter clinical trial over seven years that compared the treatment of acute uncomplicated left-sided diverticulitis with and without antibiotics with adult patients who had a history and clinical signs of acute diverticulitis, including a raised white cell count (WCC) and C-reactive protein (CRP), along with a corroborating CT scan. Exclusion criteria included radiological evidence of diverticulitis complicated by abscess, free gas or fistula, or patients taking immunosuppressive medication. Subjects were randomised to receive either intravenous fluids alone (309 patients) or in combination with broad-spectrum antibiotics (314 patients). The primary outcome marker was recurrence of symptomatic diverticulitis requiring readmission to hospital within 12 months. They also compared complications, operations and duration of hospital stay between the two groups. There was no significant difference between the two groups:

"Of 623 trial participants, 41 were lost to follow-up. In the remaining 582 patients, the rate of recurrent diverticulitis necessitating hospital readmission at 12 month follow-up was similar between the two groups (16%). The median duration of hospital stay was 3 days in both groups. The rate of complications (sigmoid perforation or abscess formation) in patients who received no antibiotics was similar to that in patients who were treated with antibiotics (1.9% vs 1.0%). There was no significant difference in the rate of sigmoid resections (during the index episode or at 12 month follow-up) between the two groups."

These findings make sense in that diverticulitis is an inflammatory bowel disorder. The authors comment on their results:

"Chabok and colleagues report that antibiotics in acute uncomplicated diverticulitis do not shorten hospital stay, prevent complications or reduce recurrence. This is the first randomised clinical trial to investigate the need for antibiotic treatment in acute uncomplicated diverticulitis and supports the conclusions of two earlier retrospective studies which suggested that antibiotics were not beneficial."

Clinicians who manage diverticulitis should keep these insights foremost in mind:

"The use of antibiotics to treat diverticulitis is based on the longstanding premise that it is caused by colonic microperforation. However, recently, it has been proposed that diverticulitis represents a form of inflammatory bowel disease and limited data suggests that mesalazine may be effective in preventing recurrent attacks. Establishing the aetiology of inflammation in diverticulitis will be an important step in determining the most appropriate therapeutic strategy."

The authors conclude by stating:

"The potential benefits of withholding antibiotic treatment include shorter hospital stays, lower costs, reduced development of bacterial resistance to antibiotics and fewer side-effects."

To this we may add reducing impediments to the sustainable long term management of diverticulitis as an inflammatory bowel disease.