Acute colonic diverticulitis: modern understanding of pathomechanisms, risk factors, disease burden and severity.

INTRODUCTION: Conservative, non-antibiotic and non-surgical management of acute diverticulitis is currently being investigated. To better inform clinical decisions, better understanding of disease mechanisms, disease burden and severity is needed.

METHODS: Literature search of risk factors, pathophysiology, epidemiology and disease burden/severity reported over the last decade.

RESULTS: Acute diverticulitis is a common disease and has a high disease burden. Incidence of hospital admissions is reported around 71 per 100,000 population, with reported increase in several subpopulations over the last decades. The incidence is likely to increase further with the aging populations. Risk factors for left-sided acute diverticulitis include dietary, anthropometric and lifestyle factors. Disease mechanisms are still poorly understood, but a distinction between inflammation and infection is emerging. The integrative and complex role of the gut microbiota has become an interesting factor for both understanding the disease as well as a potential target for intervention using probiotics. Mild, self-limiting events are increasingly reported from studies of successful non-antibiotic management in a considerable number of cases. Risk markers of progression to or presence of severe, complicated disease are needed for better disease stratification. Current risk stratification by clinical, imaging or endoscopic means is imperfect and needs validation. Long-term results from minimal-invasive and comparative surgical trials may better help inform clinicians and patients.

CONCLUSIONS: Over- and under-treatment as well as over- and under-diagnosis of severity is likely to continue in clinical practice due to lack of reliable, robust and universal severity and classification systems. Better understanding of pathophysiology is needed.