Summary: Diverticular disease is a common disorder with a wide spectrum of clinical manifestations. It can be asymptomatic (diverticulosis), cause recurrent but mild abdominal pain and bowel disturbance (SUDD), or lead to life-threatening, severe, complicated peritonitis (diverticulitis). The course of the disease is determined by genetic predisposition, changes in the intestinal microbiota modified by diet and medications, and the prevention of symptoms and their recurrence as well as treatment. In both the treatment of symptoms of diverticular disease and the prevention of recurrence, a combination therapy consisting of a modulator of intestinal microbiota that is not absorbed from the gastrointestinal tract, rifaximin-α eubiotic with prebiotic soluble fiber, is of fundamental importance. As part of the prevention of symptomatic uncomplicated diverti-cular disease and inflammation, all patients with diverticular disease, regardless of symptoms, should follow a diet rich in soluble fiber.