Last reviewed: 27 Oct 2020
Last updated: 08 Jan 2019
30 Jun 2020

US FDA approves tenapanor for the treatment of constipation-predominant IBS

The US Food and Drug Administration (FDA) has approved tenapanor for the treatment of irritable bowel syndrome with constipation (IBS-C) in adults. Tenapanor inhibits gastrointestinal sodium/hydrogen exchanger 3, reducing re-absorption of sodium from the small intestine and colon, which increases water secretion into the intestinal lumen and softens the stool.

See Management: approach

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History and exam

Key diagnostic factors

  • presence of risk factors
  • abdominal discomfort
  • alteration of bowel habits associated with pain
  • abdominal bloating or distension
  • normal examination of abdomen

Other diagnostic factors

  • passage of mucus with stool
  • urgency of defecation

Risk factors

  • physical and sexual abuse
  • PTSD
  • age <50 years
  • female sex
  • previous enteric infection
  • family history
  • family and job stress

Diagnostic investigations

Investigations to consider

  • fecal occult blood test
  • serologic tests for celiac disease
  • faecal calprotectin
  • fecal lactoferrin
  • serum CRP
  • 48-hour stool collection for total bile acids
  • serum fibroblast growth factor 19
  • 23‐seleno‐25‐homotaurocholic acid (SeHCAT) test
  • empiric trial of bile acid binder
  • hydrogen breath test
  • stool tests for Giardia lamblia
  • plain abdominal x-ray
  • flexible sigmoidoscopy
  • colonoscopy
More investigations to consider

Treatment algorithm


Chief of Gastroenterology and Hepatology

Kelsey-Seybold Clinic

Clinical Professor of Medicine

Baylor College of Medicine


Adjunct Professor of Medicine

University of Texas Medical Branch




NS declares that he has no competing interests.

Peer reviewersVIEW ALL

Professor of Medicine and Psychiatry

School of Medicine


UNC Center for Functional GI and Motility Disorders

Chapel Hill



DD declares that he has no competing interests.

Research Fellow

Department of Gastroenterology

St Mark's Hospital

Northwick Park




SM declares that he has no competing interests.

Clinical Research Fellow

Division of Medicine

Imperial College




HW declares that he has no competing interests.

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