Allergic disorders of the gastrointestinal tract were once thought of as primarily dermatological manifestations of common food allergens such as peanuts. Recently, greater attention to these products has arisen as complex mechanisms of action have been more clearly delineated. Specific disease states have recently been recognized associated with gastrointestinal reactions to foods, such as celiac disease, infantile formula protein intolerance, and eosinophilic gastroenteritis have been well described. More recently, eosinophilic esophagitis and allergic constipation have been described. This article will review current information regarding the commonly identified gastrointestinal allergic states, and more detailed information regarding two new allergic entities will also be described.