Acute diverticulitis is the most common complication of diverticulosis. Patients should be assessed according to their level of pain and associated systemic features of sepsis. In those in whom the pain is controlled and there are no signs of systemic sepsis and no high-risk features (immunocompromise, transplant patients, systemic immunosuppression) the patient may be treated in primary care but for those with systemic features of sepsis or high-risk features admission to hospital is required.