Ten years have elapsed since the printing of the second edition of this book. Since then there's been a veritable explosion of information coming mainly from the field of molecular diagnostics, which bear particular importance in the classification and treatment of Infantile enteropathies, disorders associated with immunodeficiencies, the classification of intestinal polyps and polyposis syndromes in childhood, cholestatic and metabolic disorders of childhood, liver tumors and transplantation pathology, all of which were major subjects explored in our previous editions. In this updated third edition, most of the chapters have been extensively revised to incorporate updated understanding in pathogenesis and terminology. For example, the widespread use of genetic panels and next generation sequencing in the diagnosis of cholestatic disorders of infancy and childhood, not widely available when the last edition was being prepared, prompted the writing of an entirely new chapter reflecting these advances by a new set of authors. Similarly, progress in diagnosis and classification of liver tumors justified an entirely new chapter on liver tumors that incorporates newer patient stratification in treatment protocols and reflects the new WHO classification of liver tumors. Pathology of Pediatric Gastrointestinal and Liver Disease 3rd Edition  provides the pediatric pathologist, the GI or general pathologist, and the pediatric gastroenterologist with the most complete and current reference on the subject. It includes in-depth discussions on disorders and issues that are frequently encountered but for which up-to-date information is often not readily available, as well as infrequent disorders unique or specific to children that are not covered in standard texts.