IGHE and allergic disease: This elimination-reintroduction sequence is the only way of reliably diagnosing gastrointestinal manifestations of non-IgE-mediated CMA in infants such as infantile allergic proctocolitis, mild-to-moderate allergic enteropathy and cow’s milk-induced gastro-oesophageal reflux or constipation because there is no allergy skin or blood test for non-IgE-mediated food allergy.