Over the last decade, eosinophilic gastrointestinal diseases have emerged as increasingly recognised diseases affecting both adults and children. While the exact morbidity is uncertain, it has become evident that they carry a significant cost to affected patients. Recent investigations shed light on basic mechanisms of eosinophilic recruitment and inflammation, and suggest a critical role for Th2 cytokines, such as eotaxin, and allergen exposure in their pathogenesis. Eosinophilic oesophagitis (EO) is the best characterised of these diseases, and improved understanding of its basic biology stimulated development of new treatment regimens. Current evidence supports the use of elemental diets and systemic or topical corticosteroids to treat EO. A major clinical problem is the fact that most patients relapse when medical treatment is discontinued, thus making nutritional management an attractive long term option. Many areas remain unanswered in the management of patients with EGIDs, including identification of optimal treatment protocol, development of appropriate non-invasive monitoring, and choice of appropriate therapeutic endpoints.