Mawdsley et al raise the important question as to whether patients with irritable bowel syndrome (IBS) would gain as much symptomatic improvement if recommended to exclude the top four foods (yeast, milk, whole egg, and wheat) compared with an IgG antibody test based diet.¹ In other words, does the test add specificity? This requires a trial which compares patients receiving an IgG antibody test based diet to those advised to …