Tenapanor is an inhibitor of the sodium-proton (Na(+)/H(+)) exchanger NHE3 and reduces sodium absorption in the GI tract, thus increasing intestinal fluid. Ardelyx has completed Phase 3 development of tenapanor for the treatment of irritable bowel syndrome with constipation (IBS-C) and submitted a new drug application to the U.S. Food and Drug Administration for the treatment of patients with IBS-C. In addition, tenapanor successfully completed phase III clinical trial for the treatment of hyperphosphatemia in people with end-stage renal disease who are on dialysis and RDX013, a potassium secretagogue program for the potential treatment of high potassium, or hyperkalemia, a problem among certain patients with kidney and/or heart disease.