In our accompanying mRNA-seq analysis of these IBS-M biopsy samples, this decrease in active anion secretion in the Ussing chamber was accompanied by a lower expression of components of the active chloride secretion system, namely NKCC1 and CFTR, supporting and in part explaining the finding of a functional downregulation of active anion secretion in the colon of our patients. The gene discussed is SLC12A2; the disease is irritable bowel syndrome.