Current concepts in management of acute uncomplicated left sided colonic diverticulitis

Acute left sided colonic diverticulitis (ALCD) is a common problem encountered by surgeons in the acute setting. It encompasses a variety of conditions, ranging from localized diverticular inflammation to perforation and fecal peritonitis. Daily decisions in the diagnosis and treatment of acute diverticulitis generally often depend on clinicians’ personal preferences rather than evidence-based medicine.

For the past three decades, the Hinchey classification has been the most commonly used classification for complicated ALCD in international literature. The management of ALCD has recently changed dramatically in recent years, due to better radiological imaging and availability of non-surgical treatment options. Computer tomography (CT) imaging has become a primary diagnostic tool in the diagnosis and staging of patients with acute diverticulitis and more detailed information provided by CT scans led to several modifications of the Hinchey classification. A proposal for a CT guided classification of left colon acute diverticulitis was published in 2015 by the WSES acute diverticulitis working group. It is a simple classification system of acute diverticulitis based on CT scan findings. It may guide clinicians in the management of acute diverticulitis and may be universally accepted for day to day practice. The WSES classification divides acute diverticulitis into 2 groups: uncomplicated and complicated. In the event of uncomplicated acute diverticulitis, the infection does not extend to the peritoneum. In the event of complicated acute diverticulitis, the infectious process proceeds beyond the colon.


Stage 0: Diverticula, thickening of the colonic wall or increased density of the pericolic fat


Stage 1a: Pericolic air bubbles or little pericolic fluid without abscess (within 5 cm from inflamed bowel  segment)

Stage 1b: Abscess ≤ 4 cm

Stage 2a: Abscess > 4 cm

Stage 2b: Distant air (>5 cm from inflamed bowel segment)

Stage 3: Diffuse fluid without distant free air (no hole in colon)

Stage 4: Diffuse fluid with distant free air (persistent hole in colon)

The utility of antibiotic therapy in acute uncomplicated diverticulitis has been a point of controversy in the international medical community. Although several guidelines have suggested antibiotic treatment in patients with uncomplicated diverticulitis and systemic inflammatory manifestations, in the last few years several studies demonstrated that antibiotic treatment therapy can be avoided in immunocompetent patients with uncomplicated diverticulitis. The current consensus is that uncomplicated diverticulitis may be a self-limiting condition in which local host defenses’ can manage the bacterial inflammation without antibiotics in immunocompetent patients. In this context antibiotics may, therefore, not be necessary in the treatment of uncomplicated disease. A multi-centre randomized trial involving ten surgical departments in Sweden and one in Iceland recruited 623 patients with computed tomography-verified acute uncomplicated left-sided diverticulitis was published in 2012 by Chabok et al.. Patients were randomized to treatment with (314 patients) or without (309 patients) antibiotics. Antibiotic treatment for acute uncomplicated diverticulitis neither accelerated recovery nor prevented complications or recurrence. It should therefore be reserved for the treatment of complicated diverticulitis. Another  prospective single-arm study analyzed the safety and efficacy of symptomatic (nonantibiotic) treatment for CT-proven uncomplicated diverticulitis during a 30-day follow-up period. Overall, 161 patients were included in the study, and 153 (95 %) completed the 30-day follow-up. A total of 14 (9 %) patients had pericolic air. Altogether, 140 (87 %) patients were treated as outpatients, and 4 (3 %) of them were admitted to the hospital during the follow-up. None of the patients developed complicated diverticulitis or required surgery, but, 2 days (median) after inclusion, antibiotics were given to 14 (9 %, 6 orally, 8 intravenously) patients.

If antimicrobial therapy is necessary oral administration of antibiotics may be equally as effective as intravenous administration. A randomized controlled trial of oral versus intravenous therapy for clinically diagnosed acute uncomplicated diverticulitis was published in 2009. Oral and intravenous regimens utilizing ciprofloxacin and metronidazole were compared. No patients had to be converted to intravenous antibiotics from the oral group. There was a complete resolution of symptoms in both groups.

In immunocompromised patients antibiotics with a broader-spectrum should be used. No studies have examined the value of dietary restriction or bed rest.

Outpatient management is suggested for patients with uncomplicated acute diverticulitis, with no comorbidities. These patients should be clinically monitored as outpatients and re-evaluated within 7 days to assess for resolution of the inflammatory processes. Earlier revaluation should be necessary if the clinical condition deteriorates. Etzioni et al in 2010 published a retrospective analysis, demonstrating that outpatient treatment was effective for the vast majority (94 %) of patients suffering from acute diverticulitis. A systematic review on outpatient management of acute uncomplicated diverticulitis was published in 2014. Jackson et al. concluded that current evidence suggested that a more progressive, ambulatory-based approach to the majority of cases of acute uncomplicated diverticulitis was justified. Rodríguez-Cerrillo et al. have shown that elderly patients with co-morbidities can be safely treated at home avoiding hospital admission. The DIVER trial has demonstrated that outpatient treatment may be safe and effective in selected patients with uncomplicated acute diverticulitis and can reduces the costs without negatively influencing the quality of life of these patients. This multicenter, randomized controlled trial included patients older than 18 years with acute uncomplicated diverticulitis. All the patients underwent abdominal CT. The first dose of antibiotic was given intravenously to all patients in the emergency department and then patients were either admitted to hospital or discharged. The overall health care cost per episode was 3 times less in the outpatient treated group. No differences were observed between the groups in terms of quality of life.



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Chabok A, Påhlman L, Hjern F, Haapaniemi S, Smedh K, AVOD Study Group. Randomized clinical trial of antibiotics in acute uncomplicated diverticulitis. Br J Surg. 2012;99:532–9.

 Mali JP, Mentula PJ, Leppäniemi AK, Sallinen VJ. Symptomatic Treatment for Uncomplicated Acute Diverticulitis: A Prospective Cohort Study. Dis Colon Rectum. 2016;59(6):529–34.

 Sartelli M, Viale P, Catena F, Ansaloni L, Moore E, Malangoni M, et al. 2013 WSES guidelines for management of intra-abdominal infections. World J Emerg Surg. 2013;8:3.

Ridgway PF, Latif A, Shabbir J, Ofriokuma F, Hurley MJ, Evoy D, et al. Randomized controlled trial of oral vs intravenous therapy for the clinically diagnosed acute uncomplicated diverticulitis. Colorectal Dis. 2009;11:941–6.

Etzioni DA, Chiu VY, Cannom RR, Burchette RJ, Haigh PI, Abbas MA. Outpatient treatment of acute diverticulitis: rates and predictors of failure. Dis Colon Rectum. 2010;53:861–5.

Jackson JD, Hammond T. Systematic review: outpatient management of acute uncomplicated diverticulitis. Int J Colorectal Dis. 2014;29:775–81.

Rodrìguez-Cerrillo M, Poza-Montoro A, Fernandez-Diaz E, Matesanz-David M, Inurrieta RA. Treatment of elderly patients with uncomplicated diverticulitis, even with comorbidity, at home. Eur J Intern Med. 2013;24:430–2.

Biondo S, Golda T, Kreisler E, Espin E, Vallribera F, Oteiza F, et al. Outpatient versus hospitalization management for uncomplicated diverticulitis: a prospective, multicenter randomized clinical trial (DIVER Trial). Ann Surg. 2014;259:38–44.