Acute diverticulitis is defined by diverticular and peridiverticular inflammation and infection and is efficiently treated medically in most of the cases. For most patients, outpatient treatment is possible and hospitalization is only indicated if the patient is unable to eat, suffers from an acute attack, has diverticulitis related complications or if symptoms fail to improve despite adequate outpatient therapy The treatment of acute uncomplicated diverticulitis usually consists of broad-spectrum antibiotics covering both aerobic and anaerobic bacteria. Antibiotic therapy is usually administrated for 7 to 10 days but its duration can be longer if any complications occur. If there is no clinical improvement within 2 or 3 days, repeat CT imaging is needed, as this may reveal an abscess, phlegmon or fistula, which may require percutaneous drainage or surgery. The published literature does not support the recommendation of any prophylactic diet or medical treatment for reducing the risk of first or recurrent diverticulitis in patients with diverticulosis.