Crohn's disease (CD) is a subtype of inflammatory bowel disease (IBD) that can affect any part of the intestine and can lead to stricture, fistula, and abscess if left untreated. This book highlights the key aspects of the current state of the art of pathogenesis, diagnosis, and therapy for CD and its unique complications. CD has evolved from clinical observations to a network of advanced therapies and quality of care. Among the pathogenetic factors, a significant proportion of the latest research is focused on the gut microbiome, as rapidly changing environmental factors exert their effects primarily by altering the microbiome. This book highlights the enigmatic crosstalk between the gut microbiome and CD. Going further, CD is a great mimicker that is important to differentiate from other diseases, especially intestinal tuberculosis, which is still a significant problem in tuberculosis-endemic countries. This book addresses this issue as well. Among the diagnostic modalities, capsule endoscopy is a non-invasive, radiation-free, and accurate modality for pan-enteric evaluation. The book examines the role of capsule endoscopy in suspected and established CD, including its pros and cons in these scenarios. It also highlights technical advancements in the field. Among the complications of CD, the most dreaded is fistula. Apart from traditional medical and surgical therapies, interventional inflammatory bowel disease (IIBD) therapies like endoscopic fistulotomy and abscess drainage can decrease surgical morbidity and improve patient outcomes. The book reviews the current role and details of such therapies. Overall, this book provides insights into current advances in CD pathogenesis, diagnosis, and management.