This two-volume textbook provides a comprehensive review of both adult and pediatric gastrointestinal, hepatobiliary and pancreatic pathology. The 1st volume is dedicated to gastrointestinal tract pathology. The second volume of this book covers liver, biliary system, and pancreatic pathology. This book covers each aspect of gastrointestinal tract pathology in detail, including clinical presentation, endoscopic appearance, disease pathogenesis, gross and microscopic details of each lesion. Ancillary diagnostic methods, molecular subtypes, and prognostic workup have been detailed adequately. The book also covers diseases relevant to South-East Asia, in addition to diseases prevalent worldwide. It contains 24 chapters, categorized into four sections. Section I covers the general aspects of gastrointestinal pathology including normal anatomy of the gastrointestinal tract, endoscopic details relevant for gastrointestinal pathologists and histopathologists, grossing techniques, utility of and details of ancillary tests needed; section II covers all benign diseases in different anatomical parts of the gastrointestinal tract; section III covers preneoplastic lesions and malignancies of the gastrointestinal tract, including a separate chapter on updated molecular classifications of gastrointestinal tract tumors arising from different segments; section IV includes a unique chapter on setting up a gastrointestinal pathology laboratory. This textbook has been written and edited by experts in the field with proven academic and research excellence and include curated contents to provide lucid and updated information to the readers. The book features more than 800 photographs, line diagrams, endoscopic and radiology pictures, gross and microscopic images. It includes 'Chapter Summary' at the end of each chapter and Learning Tips summarized after each major segment that helps the readers to reinforce the knowledge gained fromeach chapter. Chapters also contain case studies and/ or multiple-choice questions to enable readers to self-assess and learn from the explanations added. The textbook includes many unique chapters. It also covers cytological details and techniques relevant to gastrointestinal pathology. This comprehensive review of gastrointestinal pathology is a valuable resource for the faculties, gastrointestinal pathologists, cytologists, histopathologists, practicing pathologists, gastroenterologists, gastrointestinal surgeons, pathology fellows, postgraduates, clinical gastrointestinal fellows, and researchers in related fields.