Constipation that diet does not fix

The patient arrives with a list of what they have already tried: prunes, linseed, two litres of water a day, walking, probiotics, one preparation after another from the pharmacy. No effect, or a short-lived one. Test results normal.

In that situation it is worth checking something diet cannot touch: the coordination of the pelvic floor muscles during defecation.

What happens inside

Normal defecation requires a simultaneous rise in pressure inside the abdomen and release of the external sphincter and the puborectalis muscle. Those two things have to happen together.

In some people the opposite occurs: at the moment of straining, the muscles tighten instead of letting go. The anal canal closes. The harder the straining, the tighter the closure. A loop forms in which emptying takes fifteen minutes and ends with a feeling of incomplete evacuation.

This is called dyssynergic defecation, and no amount of fibre will fix it, because the problem is not the consistency of the stool.

Where it comes from

• Long-term holding back — work without access to a toilet, reluctance to use public toilets, nursery and school in childhood.
• Pain on opening the bowels — an anal fissure, haemorrhoids, a scar after birth. The body learns to clench in defence against pain and keeps that pattern long after healing.
• Chronically raised pelvic floor tone, often alongside pelvic pain and painful intercourse.
• Stress and years of tension — the pelvic floor reacts to it much as the neck does.

The consequences that eventually bring people in

Years of straining stretch the structures meant to hold the organs in place. Hence haemorrhoids, anal fissures, prolapse — and, paradoxically, incontinence of gas in someone who came in with constipation.

What therapy involves

I start with a functional examination: does the musculature release or clench during simulated straining? That single examination usually explains the whole history.

Then we work on:

• the mechanics of defecation — body position, foot placement, use of the diaphragm (a footstool changes the anorectal angle and makes an immediate difference for many people),
• learning to release the pelvic floor on demand, because that is a skill, not a reflex,
• manual release of overactive muscles and trigger point therapy,
• the rhythm of the day — a regular time, not postponing the urge, and a sensible limit on time spent on the toilet.

When to see a doctor rather than a physiotherapist

Blood in the stool, unintended weight loss, a sudden change in bowel habit after the age of 45, fever, severe abdominal pain — these require medical investigation. Physiotherapy is then a complement to treatment, never a substitute for it.

If, on the other hand, investigations have found nothing and the problem persists, there is a good chance the answer lies in the muscles.