Background: Diverticular disease of the colon is common in the Western world. With the first episode of diverticulitis, most patients will benefit from medical therapy, but in 10% to 20% of cases some complications will develop, such as intra-abdominal abscesses, obstructions, fistulas. In these conditions it is important to define the most appropriate surgical approach. Discussion: The management of diverticular disease has been successful owing to the advances in diagnostic methods, intensive care and surgical experience, but there is debate about the best treatment for some conditions. Fistulas complicating diverticulitis are the result of a localized perforation into adjacent viscera. In particular, the connection between the colon and the urinary tract is a serious anatomical abnormality that must be urgently corrected before a serious urinary infection results. Indications, timing and surgical procedures are determined by the severity of the disease and the patient’s general condition. Summary: Diverticular disease can lead to many complications. One of the most difficult to correct is an internal fistula, such as a colo-vesical fistula. The correct approach in cases where the disorder is clinically suspected has always been controversial, and the guidelines for sigmoid diverticulitis have not established the most appropriate method for diagnosis and treatment. At present, the surgical strategy for these cases requires interruption of the fistula and resection to remove the inflamed colonic segment, with or without primary anastomosis, focusing attention on the construction of the anastomosis to well vascularized and anatomically healthy tissues. It is clear, therefore, that establishing guidelines is difficult, because many pathological situations may be related to diverticulitis, and so, as our experience shows, the surgical approach has to be tailored to the patient’s general and local condition.