Motilin focuses on the pharmacology and physiology of motilin, with emphasis on its relationship to interdigestive motor activities and species differences between these two parameters. Changes in plasma motilin in relation to some gastrointestinal diseases, including peptic ulcer, cholelithiasis, chronic idiopathic constipation, dumping syndrome, and irritable bowel syndrome, are discussed. This book is comprised of 17 chapters and begins with a historical background on motilin, including its discovery and isolation. The next chapter considers the structure of motilin in pigs and cats and presents evidence for the existence of motilin in other species. The chemical synthesis, radioimmunoassay, and immunoreactivity of motilin are also examined. Subsequent chapters explore the prohormone of human motilin; morphological identification of motilin in the gut; mechanisms of motilin excitation as determined by in situ and in vitro studies; and motilin receptors. This monograph should be of interest to scientists, physiologists, clinical specialists, morphologists, pharmacologists, and biochemists.