CFTR and irritable bowel syndrome: Drugs used in IBS, depending on the subtype, include antidepressants, antibiotics, peripherally restricted opioids, as well as more specific or experimental ones, such as serotonin receptor ligands, CFTR (cystic fibrosis transmembrane conductance regulator) channel antagonists, GC-C (guanylate cyclase C), and CIC-2 (type 2 chloride ion channels) activators [3].