Constipation is usually treated as a problem of what goes in — more fibre, more water, laxatives. For many people that works.
For a substantial minority it does not, and the reason is that their constipation is not a transit problem at all. It is an outlet problem: the stool arrives at the rectum normally, but the mechanics of emptying fail. Adding fibre and laxatives to an outlet problem often makes matters worse, producing more urgency, more bloating and more straining against a pelvic floor that will not release.
This pattern — dyssynergic defaecation, where the pelvic floor contracts instead of relaxing during attempted emptying — is common, frequently missed, and treated primarily with physiotherapy and biofeedback rather than medication.
Signs your constipation may be an outlet problem
The distinction matters because it changes the treatment entirely. Outlet-type constipation typically involves:
- Straining despite soft stool — the stool is there and ready, and still will not pass
- A sense of blockage at the anus rather than higher up
- Incomplete emptying — needing to return to the toilet repeatedly
- Needing to press on the perineum, vagina or buttocks to empty (splinting)
- Spending a long time on the toilet, often twenty minutes or more
- Laxatives making things worse — more urgency and cramping but no easier emptying
- Digitation — needing to use a finger to help evacuate
- Leakage afterwards, because emptying was never complete
Slow-transit constipation, by contrast, typically involves infrequent bowel motions with genuinely hard stool and little urge to go. The two can co-exist, and assessment distinguishes them.
What dyssynergic defaecation is
Normal emptying requires a coordinated sequence: the abdominal muscles generate gentle propulsive pressure, while the pelvic floor and anal sphincter relax and descend, and the anorectal angle straightens to open the passage.
In dyssynergic defaecation that coordination fails. The pelvic floor and sphincter contract — or fail to relax — at exactly the moment they should be releasing. The result is pushing hard against a closed door.
Most people with this pattern have no idea they are doing it. It is not voluntary, and it is often a learned protective response — after painful haemorrhoids or fissure, after childbirth trauma, after years of ignoring the urge because of work or caring commitments, or as part of a wider pattern of pelvic floor overactivity.
It responds well to retraining, and biofeedback is the treatment with the strongest evidence base because it makes an invisible coordination error visible.
How it is treated
Assessment
A detailed bowel history and stool diary, plus — with your consent — assessment of pelvic floor coordination during a simulated defaecation effort. This is what identifies whether you are contracting when you should be relaxing, and whether a rectocele is contributing.
Defaecation mechanics retraining
Correct positioning with knees above hips (a footstool is genuinely effective, not a fad), a straight spine leaning forward with forearms on thighs, and — crucially — bracing outward and downward while relaxing the pelvic floor, instead of gripping and holding the breath.
Biofeedback
The core treatment for dyssynergia, with good supporting evidence. Visual feedback shows you exactly what your pelvic floor is doing during an attempted evacuation, so the paradoxical contraction becomes something you can see and then correct. See biofeedback therapy.
Pelvic floor downtraining
Where the pelvic floor is overactive at rest, treatment focuses on releasing and lengthening rather than strengthening — the opposite of what most people expect from pelvic floor physiotherapy, and the reason generic pelvic floor exercises can worsen this condition.
Rectal sensation retraining
For patients whose rectum has become insensitive after long-term stool retention, structured retraining restores awareness of the urge so the natural signal returns.
Bowel habit and routine
Working with the gastrocolic reflex — attempting after a meal, ideally breakfast — allowing unhurried time, and responding to the urge rather than deferring it. Simple, and repeatedly effective.
Fibre and fluid, adjusted properly
Soluble versus insoluble fibre matters. Insoluble fibre added to an outlet problem often increases bloating and discomfort without improving emptying. Adjustment is individualised, and sometimes means reducing fibre rather than increasing it.
Constipation and the rest of the pelvis
Chronic constipation rarely stays confined to the bowel. A loaded rectum presses directly on the bladder and shares nerve supply with it, so treating constipation frequently improves urinary urgency and frequency at the same time.
Repeated straining also loads the pelvic floor and its supporting structures over years, and is a recognised contributor to pelvic organ prolapse. Straightforwardly, chronic straining is one of the modifiable risk factors most worth addressing.
A rectocele can create a vicious circle of its own: stool collects in the bulge instead of passing, emptying is incomplete, straining increases, and the rectocele enlarges. Breaking that cycle needs both emptying technique and prolapse management together.
See your GP promptly for: a persistent change in bowel habit lasting more than three weeks, bleeding from the bowel, unexplained weight loss, abdominal pain with vomiting, or constipation that begins suddenly without an obvious cause — particularly over the age of 50.
Frequently Asked Questions
Why do laxatives not help my constipation?
Because laxatives address transit — getting stool to the rectum — and a substantial proportion of chronic constipation is an outlet problem, where stool arrives normally but the mechanics of emptying fail. If you strain despite having soft stool, feel blocked at the anus, or need to press to empty, laxatives will not resolve it and may worsen bloating and urgency. That pattern needs pelvic floor retraining instead.
What is dyssynergic defaecation?
It is a coordination problem in which the pelvic floor and anal sphincter contract, or fail to relax, at the moment they should be releasing to allow the bowel to empty. The result is pushing against a closed outlet. It is involuntary and usually unrecognised by the person doing it, and it responds well to biofeedback-assisted retraining.
Does a toilet footstool actually work?
Yes, for many people. Raising the knees above the hips straightens the anorectal angle, which reduces the effort required to empty. It is a genuine mechanical effect rather than a fad, though it works best combined with correct bracing and breathing technique — positioning alone will not overcome a pelvic floor that contracts during attempted evacuation.
Is it normal to press around the vagina or perineum to empty my bowels?
It is common but it is not normal, and it usually indicates either a rectocele or a coordination problem with emptying. Splinting is a workaround rather than a solution, and continued straining can enlarge a rectocele over time. Both underlying causes are treatable, so it is worth being assessed rather than continuing to manage around it.
Will pelvic floor exercises help my constipation?
Not necessarily, and sometimes the opposite. If your pelvic floor is already overactive and failing to relax during emptying, standard strengthening exercises can make symptoms worse. That is why assessment comes first: treatment for outlet constipation often focuses on releasing and lengthening the pelvic floor rather than strengthening it.
How long does treatment take?
Most people notice improvement within six to twelve weeks, and biofeedback-assisted retraining for dyssynergia typically involves a course of sessions over two to three months. Changes in positioning and bracing technique often produce some improvement immediately, in the first session.
Clinically reviewed by Jency Sudha, Consultant Pelvic Health Physiotherapist & Biofeedback Specialist — last updated 26 July 2026
The information on this page is for general guidance and does not replace individual clinical assessment. If your symptoms are new, worsening, or accompanied by bleeding, fever or severe pain, contact your GP or NHS 111.
If Laxatives Have Not Worked
Outlet-type constipation needs retraining, not more fibre. Assessment identifies which type you have.
Book Your ConsultationOr contact us directly: 07999 996926 | info@zylohphysio.com