A diverticulum is an outpouching of a hollow (or fluid-filled) structure in the body. Most diverticula occur in the colon. Incidences of acute diverticulitis are rising in Western countries, and are accompanied by rising healthcare costs. Çağdaş Ünlü discusses the different classification systems and the variety of conservative treatment options for acute diverticulitis. In addition, he also looks at follow-up procedures, with or without a colonoscopy, and possible risk factors of recurring diverticulitis.