Tenapanor in Previously Treated IBS-C, With Kyle Staller, MD, MPH

Patients with irritable bowel syndrome with constipation (IBS-C) who had already tried another IBS-C medication still used fewer gastrointestinal (GI) health care resources after starting tenapanor (Ibsrela). The data were presented at the American College of Gastroenterology (ACG) 2026 Annual Scientific Meeting.¹

The retrospective analysis included 470 patients from a national gastroenterology practice. Median GI-related health care resource utilization (HCRU) declined from 4.5 visits in the year before initiation to 3.0 visits in the year after (P <.001). Significant reductions were also seen among patients previously treated with ≥1 IBS-C medication, regardless of body mass index or comorbidity burden.²

“Patients right now who are trying tenapanor because it’s newer to the market have often tried other IBS-C agents and theoretically weren’t satisfied. That’s why they were trying tenapanor. What’s really nice to see is that these individuals, who theoretically probably have a predisposition to have high healthcare resource utilization because they’ve already failed one drug, actually still had that drop, and that drop was even more pronounced,” Kyle Staller, MD, MPH, director of the Gastrointestinal Motility Laboratory at Massachusetts General Hospital and first author of the analysissaid in an interview with HCPLive.

Real World IBS-C Patients Differ From Clinical Trial Populations

Staller noted that patients in IBS-C clinical trials tend to have few comorbidities and fit a narrow disease definition. The patients seen in GI offices are a broader group.

The analysis used electronic health record data from community GI practices rather than billing codes alone. Staller said this gives a clearer view of how real patients use care.

Diagnostic Delays Shape the IBS-C Patient Journey

Many patients wait a long time before receiving a confident IBS-C diagnosis, according to Staller. The diagnosis is often reached by exclusion, after other conditions have been ruled out.

Patients starting tenapanor have likely been through that process, he said. Those who had already tried another agent may represent a more refractory group, which is why the decline in HCRU in this subgroup stood out to him.

Switching Mechanisms of Action After IBS-C Treatment Failure

“Just because someone has failed one IBS-C agent does not mean that there are not other IBS-C agents with different mechanisms of action that may be beneficial. I think the tendency is to sort of give up,” Staller said. “Changing the mechanism of action, trying something different, I think can be incredibly helpful, and I think this data suggests that.”

Tenapanor inhibits sodium/hydrogen exchanger 3 (NHE3), reducing sodium absorption so that water is retained in the intestinal lumen.² Most other IBS-C therapies work by secretion.

The analysis was observational and had no comparison group. Staller noted that the reduction cannot be attributed to tenapanor alone.

Editor’s Note: [Disclosures pending verification]

References

1. Staller K, Fossa A, O’Byrne M, Scott LL. Health care resource utilization decreases among patients with constipation predominant irritable bowel syndrome following initiation of tenapanor: a real-world analysis. Poster P3082. Presented at: ACG 2026 Annual Scientific Meeting; October 12, 2026.

2. Ardelyx presents real-world data at ACG 2026 showing reduced healthcare resource utilization following IBSRELA initiation in adults with IBS-C. News release. Ardelyx. October 12, 2026.