Acute diverticulitis is an acute inflammation of colonic diverticulae that is associated with an episode of severe, prolonged, lower abdominal pain (usually on the left side), changes in bowel movements, low-grade fever, and leukocytosis. Acute diverticulitis is a significant burden in industrialised societies, accounting for 313,000 hospitalisations in the USA alone, and a trend of rising incidence has been observed. Despite the high prevalence, the management of diverticulitis and post-diverticulitis is largely based on consensus more than evidence derived from randomised clinical trials. In this review we will focus on the diagnosis and management strategies for diverticulitis and post-diverticulitis.