Adverse reactions to foods may occur when the balance between defensive mechanisms (such as enteric and gastric secretions, digestive enzymes, enteric barrier, etc) and aggressive factors (ie, gastroenteric mucosal damage, constipation, sIgA deficiency, etc) is altered. We therefore analyzed a group of patients with urticaria/angioedema syndrome due to food ingestion evaluating the association with digestive diseases. Our data provide clear evidence for high incidence of concomitant gastroenteric disorders in patients affected by adverse reactions to foods. We consider that these pathologic conditions may promote adverse reactions to foods.