This article is for educational purposes only and does not replace the advice of a qualified healthcare or nutrition professional.
Constipation affects roughly 1 in 7 adults and 1 in 3 children in the UK at any given time. It is one of those things that a surprising number of people live with for years without ever really addressing it, partly because it feels embarrassing to talk about, and partly because it's so normalised.
But chronically difficult, infrequent, or uncomfortable bowel movements are not something you just have to put up with. They're your body communicating that something in the system needs attention.
What Does Constipation Actually Mean?
Medically, constipation is typically defined as having fewer than three bowel movements per week, but that definition doesn't capture the full picture. Many people have daily bowel movements and still feel constipated because their stools are painful, hard and dry, difficult to pass, or incomplete. The experience of straining, feeling blocked, or never quite feeling empty are all part of the constipation picture too.
The Bristol Stool Chart, a validated clinical tool, classifies stool into seven types. Types 1 and 2 (hard lumps or a lumpy sausage shape) are associated with constipation and slow transit. If that's consistently what you're seeing, your gut is likely moving things through more slowly than it should be.
What's Going On in the Body?
The large intestine (colon) absorbs water from digested food as it passes through. When transit is slow, more water is absorbed, leaving stool dry, hard, and difficult to move.
This can happen for a wide range of reasons including insufficient fibre or fluid intake, physical inactivity, certain medications (particularly opioids, iron supplements, and some antidepressants), hormonal changes, stress, and underlying conditions affecting gut motility.
The gut also has its own nervous system, called the enteric nervous system, which works in close communication with the brain. This is why stress, anxiety, and disrupted sleep can all directly slow down gut transit and contribute to constipation.
Common Contributing Factors
Fibre Intake
Dietary fibre is probably the most well-known factor, and the evidence behind it is solid. Fibre adds bulk to stool and helps it move through the colon more efficiently. There are two main types: insoluble fibre (found in wholegrains, wheat bran, and many vegetables) which speeds up transit, and soluble fibre (found in oats, legumes, fruits, flaxseed and psyllium husk) which absorbs water and softens stool.
Most adults in the UK fall well short of the recommended 30g of fibre per day. Gradually increasing fibre intake from a variety of whole food sources is one of the most consistently supported strategies for improving constipation. The key word is gradually: increasing fibre too quickly without also increasing fluid intake can temporarily worsen bloating and discomfort.
Hydration
Fibre needs water to do its job. Without adequate fluid intake, increasing fibre can actually make constipation worse. Research suggests that fluid intake and fibre work synergistically to improve stool consistency and transit time. Aiming for pale yellow urine as a good indicator of hydration is a reasonable starting point for most people, though individual needs vary based on body size, activity levels, and climate.
Physical Activity
The relationship between movement and gut motility is well established. Physical activity stimulates the muscles in the intestinal walls, helping to move contents along by increasing peristalsis which is the wave of muscle contractions in the gut, speeding up gut transit time. Engaging in physical activity regularly supports overall gut health, and even a short walk post meal is beneficial.
Ignoring the Urge
When you repeatedly ignore the urge to go because it's inconvenient, you are quite literally overriding a natural reflex which can contribute to a cycle of chronic constipation. Responding to the urge promptly when possible, and giving yourself unhurried time in the bathroom can lower the risk of constipation and is important for bowel health.
Toilet Position
This might sound odd, but the position in which you sit on the toilet affects how easily you can pass stool. The modern seated toilet requires more straining than a squatting position because of the angle of the puborectalis muscle, a crucial muscle for faecal continence.
Using a footstool or squatty potty to raise your feet and bring your knees above hip level while on the toilet more closely mimics a squat and can make passing stool significantly easier.
Stress and the Gut-Brain Axis
Chronic stress activates the sympathetic nervous system, which effectively puts digestion on the back burner. For some people this manifests as diarrhoea, and for others it slows everything down. If your constipation tends to worsen during stressful periods, that is useful information. Supporting your stress response through sleep, rest, and other strategies can have a meaningful impact on gut function.
When to See a Doctor
Constipation that comes on suddenly, is getting progressively worse, or is accompanied by blood in the stool, unintentional weight loss, severe abdominal pain, or a significant change in bowel habits warrants a prompt conversation with your GP. These can occasionally be signs of something that needs medical investigation.
It's also worth speaking to a doctor if you've tried lifestyle changes consistently and are still struggling, particularly to rule out conditions like hypothyroidism, pelvic floor dysfunction, or slow transit constipation, which may need specific treatment.
Evidence-Based Strategies for Chronic Constipation
(British Dietetic Association)
The following dietary strategies may help those living with chronic constipation:
- Kiwifruit – 2 to 3 per day
- Prunes – 8 to 10 per day
- Mineral-rich water – 0.5 to 1.5L per day
- Psyllium husk – 10g per day (start low and build slowly, with plenty of water)
- Magnesium oxide – as a supplement
- Probiotics – strains Bifidobacterium lactis and Bacillus coagulans
These strategies are not to be done all at once but to trial one by one to find an appropriate solution.
In Summary
Rather than overhauling everything at once, here are some practical, low-pressure starting points:
- Gradually add more fibre-rich foods to your meals, prioritising variety.
- Increase your fluid intake, particularly water.
- Add some daily movement, even a short walk.
- Notice whether you're regularly ignoring the urge to go.
- Try a footstool in your bathroom.
- If stress is high, consider what small things might help you feel more regulated day to day.
- Trial a dietary strategy from the British Dietetic Association
Constipation is common, but it isn't something you simply have to accept. Understanding the factors that contribute to it puts you in a much better position to actually address it, without jumping straight to restriction, supplements, or quick fixes.
References:
https://onlinelibrary.wiley.com/doi/10.1111/jhn.70133
https://pmc.ncbi.nlm.nih.gov/articles/PMC11583288/
https://pmc.ncbi.nlm.nih.gov/articles/PMC11995435/
https://pmc.ncbi.nlm.nih.gov/articles/PMC5976340/
Feeling-bunged-up-dont-let-poo-be-a-taboo-constipation.html
https://www.bda.uk.com/resource/the-first-bda-evidence-based-dietary-guidelines-for-chronic-constipation-in-adults-from-evidence-to-practice.html
