At a glance
Most constipation guidance starts with the same advice: eat more fibre, drink more water, exercise regularly. For many people, these changes are sufficient. But for a significant number of people with chronic constipation, they are not — and being told to “just eat more fibre” when you have already been doing that for months is deeply frustrating.
This guide is for people who have tried the standard lifestyle approaches and are still struggling. It covers what happens next — the investigations, the treatments beyond fibre, and the conditions that may be underlying persistent constipation.
When lifestyle changes are not enough
If you have been consistently doing the following for at least four weeks without meaningful improvement, it may be time to seek further assessment:
- Eating 25 to 30 grams of fibre daily from a variety of sources
- Drinking at least two litres of water per day
- Getting regular physical activity
- Not ignoring the urge to go
- Keeping good toilet posture (feet elevated, not straining)
Consistent effort without improvement is not a personal failure. It is a signal that something beyond lifestyle factors may be contributing.
Possible underlying causes
Slow-transit constipation
In some people, the colon moves material through more slowly than normal. The muscles that propel stool along the colon contract less frequently or less effectively. Fibre and water help form the stool, but if the colon is not moving it along, increasing fibre alone will not solve the problem — and can sometimes make bloating and discomfort worse.
Pelvic floor dysfunction (dyssynergic defaecation)
The muscles involved in bowel evacuation need to coordinate correctly — the pelvic floor needs to relax while the abdominal muscles provide downward pressure. In some people, this coordination is disrupted: the pelvic floor muscles tighten when they should relax, making evacuation difficult or incomplete regardless of stool consistency.
This is more common than many people realise, and it is treatable — usually through biofeedback therapy with a specialist physiotherapist.
Medication side effects
Many commonly prescribed medications can cause or worsen constipation:
- Opioid pain relief
- Some antidepressants
- Iron supplements
- Some blood pressure medications
- Antacids containing aluminium or calcium
- Some anti-nausea medications
If constipation coincided with starting a new medication, discussing this with your prescribing doctor is important.
Thyroid disorders
Hypothyroidism (underactive thyroid) slows many body processes, including bowel motility. A simple blood test can check thyroid function.
Other medical conditions
Various conditions can affect bowel motility, including diabetes, neurological conditions, and connective tissue disorders. These are less common causes but may be worth investigating if standard approaches are not working.
Investigations your GP may consider
Blood tests
Checking for thyroid function, calcium levels, blood sugar, and other markers that may point to an underlying cause.
Transit study
You swallow capsules containing small markers, then have X-rays taken over several days to see how quickly the markers move through the colon. This can identify slow-transit constipation.
Anorectal manometry
A test that measures the pressures and coordination of the muscles around the anus and rectum. It can identify pelvic floor dysfunction and other functional issues.
Defaecating proctogram
An imaging study that visualises the anatomy and function of the pelvic floor during evacuation. It can identify structural issues like rectocoele, intussusception, or descent problems.
Colonoscopy
Not always needed for constipation, but may be recommended if there are concerning features (blood in the stool, new onset in someone over 50, weight loss, or a family history of bowel conditions).
Treatments beyond lifestyle
Osmotic laxatives
These draw water into the bowel to soften the stool and stimulate movement. Commonly used options are available over the counter or on prescription. They are generally considered safe for longer-term use under medical guidance.
Stimulant laxatives
These stimulate the muscles of the colon to contract more frequently. They are typically used for shorter periods or as rescue medication rather than daily management. Long-term use should be discussed with your doctor.
Prescription medications
For constipation that has not responded to standard laxatives, there are prescription medications that work through different mechanisms — increasing fluid secretion in the bowel, stimulating motility, or addressing specific receptor pathways. Your GP or gastroenterologist can discuss whether these are appropriate.
Biofeedback therapy
For pelvic floor dysfunction, biofeedback is the first-line treatment. A specialist physiotherapist helps you retrain the coordination of the muscles involved in evacuation. Success rates are encouraging, and it addresses the root cause rather than just managing symptoms.
Irrigation
Transanal irrigation uses water introduced into the rectum to stimulate evacuation. It is typically reserved for more severe or treatment-resistant constipation and is usually initiated under specialist guidance.
The impact of chronic constipation
Chronic constipation is not “just constipation.” It can significantly affect:
- Quality of life and daily functioning
- Mental health — frustration, anxiety, social withdrawal
- Physical health — hemorrhoids, fissures, prolapse from chronic straining
- Nutrition — bloating and discomfort affecting appetite and eating patterns
These impacts are real and valid reasons to seek thorough investigation and management rather than accepting constipation as something to live with.