Esophageal and gastric pathology are challenging, and the underlying physiology is complex. Advanced diagnostic testing is extensive, and the results can often be difficult to interpret. The impact of these findings on tailored treatment modalities has evolved as a result. This manual is therefore designed to present a comprehensive review of the various esophageal and gastric functional pathologies, diagnostic modalities and treatment options. Chapters included here focus on challenging functional pathologies encountered by both gastroenterologists and surgeons. Diagnostic modalities that are currently available are discussed, with accompanying deep analysis of the potential results. Within each chapter, clinical scenarios, testing/treatment options and a review of the literature for each option are included. Chapters will also focus on how to collaborate between specialties and develop a complex GI motility center, as well as the effect of common prior procedures on subsequent physiologic findings.No comprehensive resource currently exists that discusses the physiologic evaluation of foregut diseases, and none present an algorithmic approach to the management of these scenarios. This unique manual addresses and provides guidance to the approach, geared towards both gastroenterologists and surgeons.