IGHE and irritable bowel syndrome: For example, injection of food allergens into the cecum of patients with food sensitivities, evoked a local weal and flare reaction despite low levels of serum IgE for those antigens (87) and studies utilizing confocal laser endomicroscopy showed that perfusion of food antigens into the duodenum resulted in increased intraepithelial lymphocytes and widened intervillous spaces in the majority of IBS patients with suspected food intolerances compared to healthy volunteers (69).