Treating IBS-C: Looking Outside the Bowel

Why Treating IBS-C Often Means Looking Outside the Bowel

A 2026 Belgian consensus guideline, developed by researchers at KU Leuven and University Hospitals Leuven, proposes that effective management for many patients with irritable bowel syndrome with constipation (IBS-C) must start with a simple question: is the gut itself the problem, or is the exit blocked? Their work on Obstructed Defecation Syndrome (ODS) clarifies that constipation often stems not from slow transit but from pelvic floor dysfunction, requiring a completely different treatment approach.

A Diagnostic Algorithm to Separate Gut Motility from Pelvic Floor Dysfunction

Van de Bruaene, De Schepper, and their multi-disciplinary team of 29 specialists created a step-by-step guide for clinicians. The process begins with a comprehensive patient history and a physical examination, specifically a digital rectal exam performed by a trained professional. This exam can immediately identify signs of pelvic floor dyssynergia—a condition where the muscles contract instead of relax during a bowel movement, creating a functional obstruction. The guideline stresses that this basic evaluation is often skipped, leading to misdiagnosis and years of ineffective laxative use. For complex cases, they recommend specialized tests like anorectal manometry and defecography to visualize the dysfunction.

Pelvic Floor Physiotherapy, Not Laxatives, Is the First-Line Treatment for ODS

For patients diagnosed with ODS, the consensus is clear: standard osmotic laxatives like polyethylene glycol or stimulants like bisacodyl are not the primary solution. “The cornerstone of ODS treatment is pelvic floor rehabilitation,” states the guideline, led by physiotherapy experts Geraerts and Vandenplas. This rehabilitation primarily involves biofeedback therapy, where patients use visual or auditory signals from a sensor to relearn proper pelvic floor muscle coordination. The goal is to restore the normal “push-to-relax” reflex. The researchers note that while fiber supplementation is often advised, it must be done cautiously in ODS, as increased bulk without proper evacuation can worsen symptoms.

Integrated Management and the Limited Role of Surgery

The Belgian algorithm advocates for an integrated approach. If biofeedback fails or symptoms are severe, other conservative treatments are considered. These can include rectal irrigation or, in select cases, the temporary use of neuromodulation techniques. Surgical intervention, such as procedures to repair a rectocele or rectal prolapse, is positioned as a last resort. The consensus strongly advises that surgery only follows a minimum of six months of dedicated pelvic floor therapy and thorough psychological evaluation, as outcomes are unpredictable. This cautious stance reflects the multifactorial nature of ODS, where anatomical fixes may not resolve underlying functional habbits or gut-brain axis disruptions that contribute to symptoms.

Shifting the IBS-C Treatment Paradigm from Gut to Pelvis

This guideline represents a significant shift in clinical thinking. It moves away from a one-size-fits-all model of constipation management toward a precision medicine approach. By providing a clear diagnostic-therapeutic algorithm, it empowers clinicians to identify the large subset of IBS-C patients whose root cause is pelvic floor-related. For patients, this means the potential for faster, more accurate diagnosis and access to targeted therapies like physiotherapy that address the core mechanism of their problem, rather than just the symptom. The work directly supports the concept that IBS-C is not a single disease.

Frequently Asked Questions

How do I know if my constipation is IBS-C or Obstructed Defecation Syndrome?

A key indicator of ODS is a persistent feeling of rectal blockage or incomplete evacuation, even if the stool is soft. A gastroenterologist or specialized physiotherapist can perform a digital rectal exam to check for pelvic floor dyssynergia, which is the hallmark of ODS.

If I have ODS, will laxatives ever help?

Laxatives may provide temporary relief but do not correct the dysfunctional muscle coordination causing the obstruction. The guideline establishes pelvic floor physiotherapy with biofeedback as the necessary first treatment to retrain the muscles for long-term improvement.

Is surgery a common solution for this type of constipation?

No. The consensus guideline reserves surgery only for specific anatomical issues, like a large rectocele, and only after at least six months of dedicated pelvic floor rehabilitation has failed. Non-surgical management is the standard.

Sources:
https://pubmed.ncbi.nlm.nih.gov/42417642/
https://pubmed.ncbi.nlm.nih.gov/42347939/
https://pubmed.ncbi.nlm.nih.gov/42319080/