Ardelyx, Inc. is a biopharmaceutical company that develops and markets drugs for gastrointestinal and cardiorenal therapeutic areas. Their lead product candidate, tenapanor, is being tested in a Phase III clinical trial to combat irritable bowel syndrome and in a Phase III trial to regulate serum phosphorus in patients with chronic kidney disease. The company is also working on RDX013 and RDX020, two other treatments for electrolyte disorders in patients with chronic kidney disease.