Functional Gastrointestinal Disorders (FGIDs) or Disorders of Gut-Brain Interaction (DGBI) are characterized by abdominal symptoms without detectable structural abnormalities that could explain the symptoms. Since FGIDs are not life-threatening, they have historically been given limited attention in Japan. However, their impact on patients’ quality of life and social productivity has gained increasing recognition. Over the past three decades, a growing body of evidence has enhanced our understanding of FGIDs, leading to the development of effective therapeutic strategies. This chapter explains changes in symptom perception over time, gastrointestinal motility function test, brain-gut hormones and their functions, changes in transition of academic activities, and positioning of FGIDs defined by Rome IV criteria. The first conference of the Japanese Society of Neurogastroenterology was held in 2002, aimed to develop a new field of research called “neurogastroenterology.” The diseases discussed in this book are centered around FGID/DGBI, with surrounding diseases primarily focused on gastrointestinal motility disorders (GIMDs). Recently, drugs targeting gut-brain hormone pathways have been developed for diabetes treatment, GIP/GLP-1 receptor agonists, which have appetite suppression as a side effect “physiological action.” Advancements in gastrointestinal function tests have contributed to the understanding of pathophysiology and diagnosis. Further development of Neurogastroenterology, the study of FGID and related disorders, is expected in the future.