Constipation is one of the most common digestive issues I see in clinic. It affects people of all ages. Despite this, it’s still something many people feel uncomfortable talking about.

When people think about constipation, they often assume it simply means not going to the toilet very often. In reality, it can involve a range of symptoms that affect day-to-day comfort and wellbeing. Typical symptoms include infrequent bowel movements, hard stools that are difficult to pass, bloating and abdominal discomfort. Over time it can become a frustrating cycle, where ongoing symptoms lead to more straining or anxiety around bowel movements, which can actually make things worse.

In my work in primary care, I often see patients who have been struggling with these symptoms for quite some time before seeking advice.

One treatment that frequently comes up in discussions is psyllium husk, also known as ispaghula husk. It is sometimes recommended for constipation, but many people are unsure how it works or whether it is the right option for them.

So what actually is psyllium husk?

Psyllium husk is a type of soluble fibre that comes from the seeds of a plant called Plantago ovata. It is commonly used as a bulk-forming laxative.

When psyllium is mixed with water it forms a soft gel. This gel moves through the digestive system and helps increase the bulk of stool in the intestine.

That increased bulk gently stimulates the bowel to move, making stools softer and easier to pass.

For many people psyllium begins working within 12 to 24 hours, although it can take a couple of days to notice the full effect.

One interesting feature of psyllium is that it can help regulate stool consistency. While it is often used for constipation, it can also help firm loose stools in some situations, which is why it is sometimes recommended for people with irritable bowel syndrome.

The real issue: most of us are not eating enough fibre

One of the most common things I notice in clinic is that many people simply are not getting enough fibre in their diet.

In the UK adults are advised to eat around 30 grams of fibre each day, yet the average intake is closer to 15 grams.

Fibre plays a key role in digestive health. It helps add bulk to stool, supports bowel motility and feeds beneficial gut bacteria.

When fibre intake is too low, stools can become harder and slower to pass, which increases the likelihood of constipation.

For people whose diets are low in fibre, supplements like psyllium can sometimes be a helpful addition alongside dietary changes.

What the research tells us about psyllium

There has been considerable research looking at fibre supplementation for constipation.

Studies suggest that increasing fibre intake can significantly improve constipation compared with no treatment. Psyllium in particular appears to be more effective than some other fibre supplements, such as wheat bran.

Research has also shown improvements in stool frequency and stool consistency in people taking psyllium.

Another interesting finding is that psyllium can help regulate stool form. Because it absorbs water and forms a gel, it can soften hard stools while also helping to firm loose stools.

This stool-normalising effect is one of the reasons it is sometimes recommended for people with conditions such as irritable bowel syndrome.

Can food help constipation too?

While fibre supplements can be useful, I often start by looking at dietary changes.

Many foods naturally contain fibres that support bowel regularity, and small changes can sometimes make a bigger difference than people expect.

Foods that have been shown to help include prunes, kiwifruit, oats and flaxseeds, also known as linseeds.

Kiwifruit in particular has been studied quite extensively. Some research suggests that eating two kiwifruit per day can increase bowel movements, reduce straining and improve stool consistency.

For many people, gradually increasing fibre intake through foods can help support more regular digestion.

Something I always remind patients about: fluids

One of the first things I ask patients about when discussing fibre intake is how much fluid they are drinking.

Fibre supplements such as psyllium work by absorbing water in the gut. Without adequate fluid intake they cannot form the gel needed to soften stools and support bowel movements.

In some cases taking psyllium without enough fluid can actually worsen constipation rather than improve it.

For this reason it is important to take fibre supplements with plenty of water and to maintain good hydration throughout the day.

Constipation can feel frustrating, but it is also very common and often manageable with the right combination of dietary and lifestyle changes.

For people whose fibre intake is low, psyllium husk can be a helpful tool. However, it tends to work best when combined with a balanced diet, adequate hydration and regular movement.

If constipation persists or becomes particularly troublesome, it is always worth speaking with a healthcare professional for personalised advice.