SLC26A3 and congenital secretory chloride diarrhea 1: Overall, butyrate therapy induced a reduction of Cl- (136 mmol/l, IQR 13 vs 120 mmol/l, IQR 42; p < 0.001) and Na+ (78 mmol/l, IQR 29 vs 50 mmol/l, IQR 49; p = 0.002) fecal losses in CLD patients, but a variable response was observed in children with different SLC26A3 genotype.