Constipation in Kids: A Hidden Crisis That's Begging for Better Solutions – But Is This New Drug the Game-Changer We Need?
Picture this: millions of children battling the discomfort and pain of chronic constipation, often linked to irritable bowel syndrome with constipation (IBS-C), and the ripple effects that can last into adulthood. It's not just about tummy aches; untreated constipation can lead to serious issues like abdominal pain, secondary complications in the colon, and even things like diverticula down the line. As a pediatric gastroenterologist, I've seen firsthand how this affects families – but what if there was a more convenient, effective option on the horizon? Enter tenapanor, a promising new medication, and the latest safety data from a phase 3 trial in kids. But here's where it gets controversial: while the results look reassuring, is this drug truly safe for long-term use in growing bodies, or are we jumping the gun on something that might have unforeseen downsides?
Let's dive into the details from the 2025 North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) Annual Meeting, held in Chicago, Illinois. Researchers shared interim safety findings from the phase 3 R-ALLY trial and its open-label extension, focusing on tenapanor in pediatric patients with IBS-C. This condition, for those unfamiliar, involves recurrent abdominal discomfort accompanied by constipation, making it hard for kids to pass stools regularly. Tenapanor is a first-in-class drug that targets the sodium/hydrogen exchanger isoform 3 (NHE3) in the gut – think of it as a blocker that encourages the intestines to release more fluid, softening stools without relying on the large volumes of liquid typical in other laxatives. Preliminary results showed it was safe and well-tolerated in adolescents, with no serious adverse events tied to the treatment.
The study enrolled 77 patients aged 12 to under 18, randomly assigning them to either tenapanor at 25 mg twice daily, 50 mg twice daily, or a placebo for 12 weeks. Fifty-six who finished that phase moved into a 40-week open-label extension where everyone got the actual drug. According to the abstract, in the extension phase, no serious treatment-emergent adverse events (TEAEs) occurred. All other adverse events were deemed unrelated to the drug except for diarrhea, and even those resolved except for two mild cases: one episode of overflow incontinence (where stool leaks due to severe constipation) and one instance of diarrhea. This aligns with what we've seen in adult studies, where tenapanor has proven effective for similar conditions.
In this exclusive Q&A, Dr. Thomas Wallach, Chief of Pediatric Gastroenterology at SUNY Downstate Health Sciences University in New York, breaks down the implications. He's the expert guiding us through the safety profile and what it means for families dealing with pediatric IBS-C. And this is the part most people miss: while safety is a huge win, we're still waiting on full efficacy data – so is it time to celebrate, or should we proceed with caution?
Contemporary Pediatrics: Could you elaborate on the tenapanor study in pediatric patients with IBS-C, particularly your take on the blinded safety data from the phase 3 trial and its open-label extension?
Dr. Thomas Wallach: Tenapanor is an innovative laxative that's gaining attention not just for softening stools but also for potentially supporting the gut's protective barrier. It achieves this by inhibiting NHE3, a protein in the intestinal lining that normally helps absorb sodium and water. By blocking it, the colon produces more fluid, making bowel movements easier without the drawbacks of traditional options. Unlike osmotic laxatives such as polyethylene glycol (like MiraLAX), which require you to consume large amounts of water or liquid that stays in the intestines, tenapanor prompts the gut to naturally secrete more moisture. This can alleviate IBS-C symptoms like bloating and discomfort, much like how some other drugs work by encouraging softer, more manageable stools.
It's already shown success in adults, with strong safety records and positive results for IBS-C or chronic constipation. This pediatric trial, targeting ages 12 to 18, is part of an ongoing effort to confirm its benefits in younger populations, with another study on the horizon for even smaller children. As a doctor, I'm excited about the potential to fill a gap in treatment options.
Contemporary Pediatrics: What key results from the study were highlighted at NASPGHAN 2025?
Dr. Wallach: When we adapt a medication from adults to children, two critical questions arise: Does the underlying condition behave similarly, meaning will the drug's mechanism translate? And are there unexpected safety concerns unique to kids, since they're not just miniature versions of adults? Organs develop and function differently at various ages – what might be harmless in grown-ups could pose risks in children, or vice versa. We always prioritize these aspects in pediatric research.
This abstract focuses on safety signals from the nearly complete trial, comparing 12- to 18-year-olds on standard tenapanor doses against a control group. We're pleased to report that, aside from minor issues like loose stools – which you'd expect from any laxative – no significant adverse events stood out. This mirrors the adult data, suggesting we're primarily dealing with the typical side effects of bowel-relief treatments, such as occasional over-eagerness in the bathroom. It's highly reassuring and gives me confidence in preliminary use of tenapanor in pediatrics. We also have early efficacy hints that match adult outcomes, pointing to a likely positive full report when the trial wraps up.
But remember, this study doesn't confirm effectiveness yet. Safety and efficacy are the twin pillars of any treatment. While I feel okay about trying tenapanor in tough cases based on this profile, I wouldn't recommend it universally without proven results. For context, our go-to pediatric constipation treatments fall into two main categories: stool softeners and bulking agents (think fiber supplements, MiraLAX, or lactulose, which draw in water to ease passage) and prokinetic or stimulant options (like Senna or Ex-Lax, which irritate the bowel to promote movement). Each has drawbacks – fiber can cause gas, MiraLAX requires drinking copious amounts of a sometimes unappealing liquid, and stimulants may lead to cramping or dependency.
In pediatrics, especially with neurodivergent kids who struggle with sensory issues, compliance is a big hurdle. A large-volume, bland-tasting drink like MiraLAX might be rejected, leading to worsening symptoms. Other pill or small-volume alternatives exist but aren't as thoroughly studied, often lack pediatric approvals, and can be pricey with mediocre results. There's a real demand for compact, potent laxatives, particularly for children with IBS-C who can't handle big drinks, those with stomach volume limits due to illness, or cases where irritants could complicate things. Constipation is epidemic – affecting roughly half the population at some point – driving abdominal pain that persists into adulthood and risks like colon issues.
Addressing it early is crucial because the colon functions like a muscle: fix it in childhood, and you're less likely to battle it later, as tissues heal better young. Yet, some might argue that introducing a new drug prematurely could sideline tried-and-true methods or overlook long-term effects. What if tenapanor alters gut development in ways we haven't seen? It's a conversation worth having.
Reference
Williams N, Wallach T, Ringheanu M, et al. SAFETY AND TOLERABILITY OF TENAPANOR IN PEDIATRIC PATIENTS WITH IRRITABLE BOWEL SYNDROME WITH CONSTIPATION: AN ANALYSIS OF BLINDED SAFETY DATA FROM A PHASE 3 STUDY AND ITS OPEN-LABEL EXTENSION. Abstract. Presented at: 2025 NASPGHAN Annual Meeting. November 5-9, 2025. Chicago, Illinois.
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Do you believe tenapanor could transform how we treat pediatric constipation, or are we potentially ignoring subtle risks that might emerge over time? Should we prioritize novel drugs over established ones, especially for kids? Weigh in with your opinions in the comments – let's discuss!
