The development of clinical and histopathological criteria for the diagnosis of Crohn's disease (CD) and ulcerative colitis (UC), pushed the scientists to identify a new category: the indeterminate colitis (CI). This term is used when definitive diagnosis of UC or CD has not been made by colonoscopy, colonic biopsy or colectomy. The distinction between these forms has major implications including the choice of medical treatment, timing of surgery, prognosis and disease course. The role of surgery in inflammatory bowel disease differs between the three main forms: in CD is primarily to treat complications of the disease process; in UC surgery is curative for intestinal manifestations and nearly eliminates the risk of future malignancy; in IC is actually discussed: the current guidelines identify in surgery the best treatment for fulminate disease, intractability of disease symptoms or failure of medical therapy. Although there is a few number of studies in the literature, selective criteria for the diagnosis and successful treatment must be revisited. The term CI should be used as a pending tray diagnosis, representing diagnostic inadequacy and not as specific nosological entity. Evidence emerging from the studies of serological markers (ASCA and P-ANCA) suggests that a subgroup of patients initially diagnosed as IC maybe identified as a separate group, and so they need a specific treatment for their disease.