Constipation: common causes, everyday habits and when to see a doctor

Constipation is common, and it affects people of all ages. The UK's National Health Service (NHS) says that simple changes to diet and lifestyle are usually enough to get things moving again. In the United States, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health, estimates that about 16 in 100 adults have symptoms of constipation, and about 33 in 100 adults aged 60 and over.

Below: what counts as constipation, what commonly causes it, the everyday habits that can help, when a pharmacist can help, and the signs that mean you should see a doctor.

What counts as constipation?

The NHS says it is likely to be constipation if:

• you have had fewer than 3 poos in the last week, or you are pooing less often than usual;
• your poo is unusually large or small, and dry, hard or lumpy;
• you are straining or in pain when you have a poo;
• you feel you have not fully emptied your bowels.

You may also have a stomach ache and feel bloated or sick.

People have different bowel patterns, and NIDDK points out that only you know what is normal for you. It also notes that constipation is not a disease in itself, but it can be a symptom of another medical problem, and it can last a short or a long time.

If you look after an older person, or someone with dementia or a learning disability, the NHS warns that constipation can be easily missed. Look out for changes in behaviour, such as confusion, which might mean they are in pain or discomfort.

What commonly causes constipation?

Sometimes there is no obvious reason. The most common causes on the NHS list are:

• not eating enough fibre, which is found in fruits, vegetables and cereals;
• not drinking enough fluids;
• not moving enough, and spending long periods sitting or lying down;
• often ignoring the urge to go to the toilet;
• changing your diet or daily routine;
• a side effect of a medicine;
• stress, anxiety or depression.

Changes to your routine can also play a part: NIDDK lists travel, pregnancy and getting older among them. In its advice for Ramadan, the British Dietetic Association (BDA) notes that bowel habits can change when different foods are eaten at different times of day.

Constipation is common during pregnancy and after giving birth, and it is more common over the age of 65, according to the NHS. NIDDK adds that people who eat little fibre, and people with functional gut disorders such as irritable bowel syndrome, are more likely to become constipated.

Medicines can play a part. NIDDK lists medicines and dietary supplements that can make constipation worse, including antacids that contain aluminium and calcium, opioid painkillers, some medicines for depression, and iron supplements. Do not stop or change a medicine without speaking to your doctor first.

Less often, constipation is linked to a health condition. NIDDK names conditions such as coeliac disease, an underactive thyroid and diabetes, and the NHS mentions diverticular disease and bowel cancer, while stressing that this is rare.

How can fibre help?

Fibre helps make poo softer and easier to pass. The NHS reports that UK government guidelines recommend 30g of fibre a day for adults, while most adults eat only about 20g. NIDDK gives a range of 22 to 34 grams a day for adults, depending on age and sex.

Increase it gradually. NIDDK advises adding fibre a little at a time so your body gets used to the change. In its advice on IBS, NIDDK notes that too much fibre at once can cause gas; our guide to gas and bloating explains where gas comes from.

The NHS also suggests adding some wheat bran, oats or linseed to your diet. On food labels, it describes foods with 6g or more of fibre in every 100g as high in fibre.

Foods with little or no fibre are worth going easy on. NIDDK lists crisps, fast food, meat, and prepared and processed foods such as some frozen meals and snack foods.

How much should you drink?

Fluids help the fibre work. The NHS advises drinking plenty of water and other fluids and avoiding alcohol. NIDDK explains that water and other liquids help fibre make stools softer, and suggests asking a health professional how much you need, based on your size, health, activity level and where you live.

If you fast during Ramadan, the BDA suggests having plenty of fluids between iftar and suhoor and keeping up a fibre-rich diet of fruit, vegetables and wholegrains. Our guide to IBS and fasting has more on eating during Ramadan.

Does moving more help?

Yes. The NHS says a daily walk or run can help you poo more regularly, and NIDDK says regular physical activity may help with symptoms. For gentle activity, the BDA mentions walking and yoga, and points to UK recommendations of 30 minutes a day, or 150 minutes spread through the week.

What toilet habits help?

The NHS and NIDDK suggest:

• Keep to a regular time and place, and give yourself plenty of time.
• Do not delay when you feel the urge to go.
• Try going at the same time each day, for example a little while after your morning meal: NIDDK explains that eating helps your colon move stool along.
• Rest your feet on a low stool while you sit on the toilet. If possible, raise your knees above your hips.
• Try to relax your muscles.

The NHS notes that you may notice a difference within a few days, though sometimes it takes a few weeks for symptoms to improve.

When can a pharmacist help?

Speak to a pharmacist if changes to your diet and lifestyle are not helping, as the NHS advises. Your pharmacist, doctor or a registered dietitian can advise on options, and a pharmacist can tell you whether you should see a doctor.

Before an appointment, it can help to keep notes. NIDDK suggests tracking how often you go and what your stools look like for several days or weeks. Your doctor is likely to ask about your eating habits, how active you are, any medicines you take and how long you have had symptoms. They may arrange blood or stool tests to look for a cause.

Long-term constipation can lead to faecal impaction, where poo builds up in the last part of the bowel. The NHS explains that the main symptom is diarrhoea leaking around the build-up of hard poo. It needs a doctor or nurse. Do not try to remove it yourself.

When to see a doctor

The NHS advises seeing a GP if you:

• are constipated and it is not getting better with the changes above or with advice from a pharmacist;
• are regularly constipated, or regularly bloated;
• have blood in your poo;
• have lost weight without trying;
• are constipated and feel tired all the time;
• are taking a medicine that is causing constipation, such as an opioid painkiller;
• notice a sudden change in how you poo;
• have tummy pain.

NIDDK also advises seeing a doctor if your symptoms do not go away with self-care, or if you have a family history of colon or rectal cancer. Speak to your doctor before you stop taking any prescribed medicine.

See a doctor right away, NIDDK advises, if you have constipation together with any of these:

• bleeding from your bottom, or blood in your poo;
• constant pain in your tummy;
• being unable to pass gas;
• vomiting;
• a fever;
• lower back pain;
• weight loss without trying.