Editor,—Following their studies of whole gut lavage fluid, Smyth et al have suggested that a non-idiopathic intestinal inflammation occurs constituitively in patients with cystic fibrosis (CF), as a consequence of a proinflammatory effect of the patient's CFTR mutations.1They reported marginally elevated excretion of IgG, IgM, interleukin 1 (IL-1), neutrophil elastase, and eosinophil cationic protein, and much more significant increase in excretion of IL-8 and albumin, but no increase in excretion of α₁ antitrypsin or IgA. In this …