The goal to create a standardized diagnostic classification scheme of food-related gastrointestinal hypersensitivity disease syndromes included the diagnosis of eosinophilic gastroenteritis. This article reviews the history of this diagnosis and the current concepts of this complex disorder. The common symptoms from the literature are discussed. Because no standards for this diagnosis exist, the wide variety of diagnostic criteria from the literature are presented. No consistent immunologic abnormalities have been associated with the diagnosis of eosinophilic gastroenteritis in the literature. A review of the current immunologic concepts associated with the diagnosis of eosinophilic gastroenteritis is presented. The history of this disorder, which spans more than 6 decades is also discussed. The contributions made by the original authors during this period are presented. Attention was directed to the variety of clinical features associated with this disorder, but particular attention was paid to the evolution of the pathophysiologic mechanisms proposed. Some of the difficulties associated with the prospective study of patients with eosinophilic gastroenteritis are also discussed. The establishment of appropriate control populations, as well as the fundamental difficulties encountered with the establishment of the certainty of the link between abnormal immunohistochemical findings, and initial clinical symptoms are presented and discussed. A new classification system is proposed for food-related gastrointestinal hypersensitivity disease syndromes. Age, symptoms, and the region of the gastrointestinal tract involved were the variables that were considered most important by consensus opinion. Finally, recommendations to refocus our collective investigative efforts are presented.