A gastrointestinal food allergy can be mediated by IgE, such as in gastrointestinal anaphylaxis and oral allergy syndrome, or, more commonly, by non-IgE mediated or mixed mechanisms, as in food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), eosinophilic esophagitis (EoE) and eosinophilic gastrointestinal disease (EGID) [58]. This evidence concerns the gene IGHE and eosinophilic gastrointestinal disease.