Porcine Intestinal Adenomatosis (PIA) is a disease affecting the alimentary tract of pigs. Previous literature has described several syndromes relating to PIA, including Regional Ileitis (RI), Necrotic Enteritis (NE), and Proliferative Hemorrhagic Enteropathy (PHE). However, it wasn't until recently that morphologic evidence was found, linking all four syndromes with a single etiologic agent. A clinical review of PIA, including incidence and prevalence, etiology, lesions, diagnosis, treatment and control, follows.