Diverticular disease and diverticulitis are the most common non-cancerous pathology of the colon. It has traditionally been considered a disease of the elderly and associated with cultural and dietary habits. There has been a growing evolution in our understanding and the treatment guidelines for this disease. To provide an updated review of the epidemiology, pathogenesis, classification and highlight changes in the medical and surgical management of diverticulitis. Diverticulitis is increasingly being seen in young patients (< 50 years). Genetic contributions to diverticulitis may be larger than previously thought. Potential similarities and overlap with inflammatory bowel disease and irritable bowel syndrome exist. Computed tomography imaging represents the standard to classify the severity of diverticulitis. Modifications to the traditional Hinchey classification might serve to better delineate mild and intermediate forms as well as better classify chronic presentations of diverticulitis. Non-operative management is primarily based on antibiotics and supportive measures, but antibiotics may be omitted in mild cases. Interval colonoscopy remains advisable after an acute attack, particularly after a complicated form. Acute surgery is needed for the most severe as well as refractory cases, whereas elective resections are individualized and should be considered for chronic, smoldering, or recurrent forms and respective complications (stricture, fistula, etc
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) and for patients with factors highly predictive of recurrent attacks. Diverticulitis is no longer a disease of the elderly. Our evolving understanding of diverticulitis as a clinical entity has led into a more nuanced approach in both the medical and surgical management of this common disease. Non-surgical management remains the appropriate treatment for greater than 70% of patients. In individuals with non-relenting, persistent, or recurrent symptoms and those with complicated disease and sequelae, a segmental colectomy remains the most effective surgical treatment in the acute, chronic, or elective-prophylactic setting.