Gastroenterology explores the structure, function, and disorders of the digestive tract and accessory organs. This textbook walks readers from basic GI physiology to comprehensive management of disorders — dyspepsia, IBD, hepatobiliary disease, pancreatitis, and colorectal pathology. Diagnostic and procedural skills (endoscopy, imaging interpretation) are integrated with medical therapies, nutritional care, and rehabilitation. Evidence-based algorithms, multidisciplinary care pathways, and patient communication tips make clinical application straightforward. An essential resource for gastroenterology fellows, internists, and surgeons involved in digestive-health care.