Constipation is one of the most common digestive complaints: what counts as constipation, why it happens, what to change in your diet and daily habits, and when you should see a doctor.
Almost everyone deals with constipation at some point. Most of the time it is short-lived: your routine changes, you travel, or you eat differently for a few days. According to the World Gastroenterology Organisation (WGO), chronic constipation affects roughly 9–20% of adults, and women experience it about twice as often as men [5].
In this article we draw on information from the UK National Health Service (NHS), the US National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Mayo Clinic, WGO guidelines and the Rome IV criteria, which doctors use to assess functional bowel disorders. You will find the sources at the end of the article, and they are marked with numbers in the text, for example [1]. If you want to understand how food travels through your digestive tract, start with our article “Digestion: how it works and how long it takes”.
What is constipation?
Constipation means you go to the toilet less often than usual or find it hard to pass stools. The NHS says it is worth paying attention if you have pooed fewer than 3 times in the past week, or less often than is normal for you [1]. Going less often is not a problem in itself, though: what matters most is your usual rhythm and any changes to it.
Common signs
- Going less often. Fewer than 3 times a week, or less often than usual [1].
- Hard, dry or lumpy stools. They may be unusually large or small [1].
- Straining. Passing stools can be painful [1].
- A feeling that your bowels haven't fully emptied. You may also feel bloated, have tummy ache or feel sick [1].
What do the Rome IV criteria say?
Doctors assess long-term, so-called functional constipation using the international Rome IV criteria [4]. Put simply, at least two of the following must be present, in more than one in four bowel movements:
- Straining when passing stools.
- Hard or lumpy stools.
- A feeling of incomplete emptying.
- A feeling of blockage at the back passage.
- Needing to help yourself manually.
- Fewer than 3 spontaneous bowel movements a week.
The symptoms must have been present for the last 3 months and have started at least 6 months earlier [4]. These criteria are meant for doctors, so don't try to diagnose yourself with them. They simply show that one or two difficult mornings are not a disease.
Causes of constipation
Most often, constipation is caused by lifestyle rather than illness. The NHS and NIDDK highlight several main groups of causes [1, 2].
- Too little fibre. Fibre adds bulk to stools and holds on to water [3]. How much you need is covered in our article “How much fibre do you need a day?”.
- Too little fluid. If you drink too little, stools become drier and harder [1, 2].
- Not moving enough. Long periods of sitting or lying down slow the bowel down [1].
- Ignoring the urge to go. If you often “wait until later”, your bowel rhythm can be disrupted [1, 2].
- Changes to routine and diet. Travel, a different time zone, unfamiliar food [2].
- Stress and anxiety. The NHS also lists these among the causes [1].
- Life stages. Constipation is more common during pregnancy, after giving birth and in older age [1, 2].
Some medicines and supplements
NIDDK lists groups of medicines that can cause constipation: some antacids containing aluminium or calcium, opioid painkillers, some antidepressants, anticonvulsants, calcium channel blockers, diuretics, medicines for Parkinson's disease and iron supplements [2].
If you notice that constipation started after you began a new medicine, talk to your doctor or pharmacist. Don't stop prescribed medicines on your own: the NHS advises speaking to your doctor first [1].
Less common but important causes
Sometimes constipation is a sign of another condition, such as a thyroid disorder, diabetes, coeliac disease, irritable bowel syndrome or pelvic floor problems [2]. In rare cases it can be caused by bowel disease, including bowel cancer [1]. That is why warning signs should never be ignored; we cover them below.
Constipated? What to do day to day
Medical organisations recommend looking at your diet and habits first [3, 5]. It isn't a quick fix, but it is usually the best place to start.
- Increase fibre gradually. The 2025 WGO guidelines suggest slowly increasing total fibre to 20–30 g a day over several weeks, not several days [5].
- Drink enough fluids. NIDDK stresses that fluids help fibre work and soften stools [3]. Water is the best choice.
- Move every day. A daily walk or run can help [1]. WGO mentions brisk walking, cycling and swimming [5].
- Don't put it off. When you feel the urge, go to the toilet and give yourself enough time [1].
- Build a routine. Try to go at a similar time each day, for example after breakfast [1].
- Raise your feet. The NHS suggests resting your feet on a low stool so your knees are higher than your hips [1].
- Plan ahead when travelling. Bring a water bottle, some fruit or nuts, and try to keep your usual mealtimes.
Diet and constipation: what do the guidelines say?
EFSA considers 25 g of fibre a day adequate for normal bowel function in adults [8]. NIDDK gives 22–34 g a day, depending on age and sex [3]. Yet most people eat considerably less.
What to eat more often
- Wholegrains. Wholemeal bread and pasta, oats, bran [1, 3].
- Pulses. Lentils, beans, chickpeas, peas [3].
- Fruit and berries. The NHS mentions apples, apricots and berries [1], and NIDDK adds oranges and pears [3]. Eat apples with the skin on.
- Vegetables. Carrots, broccoli, green peas, leafy greens [3].
- Nuts and seeds. Almonds, peanuts, linseed [1, 3].
What to limit
NIDDK advises limiting foods with little or no fibre: crisps, fast food, processed meat and ready meals [3]. The NHS also reminds you to keep alcohol in check [1].
How much fibre is in common portions?
| Food | Portion | Fibre |
|---|---|---|
| Wholemeal bread | 2 slices | about 7 g |
| Wholemeal spaghetti with pesto | 150 g | about 6 g |
| Baked potato with skin | 180 g (medium) | about 5 g |
| Porridge oats (raw) | 50 g | about 4 g |
| Nuts (walnuts, almonds) | 40–50 g | about 4 g |
| Baked beans in tomato sauce | 80 g | about 3 g |
| Broccoli and cherry tomatoes | 80 g | about 2 g |
| Apple or banana | 1 medium | about 2 g |
| Frozen raspberries | 50 g | about 1.3 g |
As you can see, these foods alone can provide more than 30 g of fibre a day. The BDA's sample menu adds up to about 38 g [9].
Why fibre and water go together
Fibre draws water into the bowel. The BDA points out that if you increase fibre but drink too little, you may become short of fluids [9]. So increase fibre and water together. The 2010 WGO guideline mentions up to 1.5–2 litres of fluid a day alongside fibre [6], but your needs depend on your size, health, activity level and the weather, so it's worth discussing with your doctor [3].
Another reason to go slowly is that a sudden increase in fibre can cause bloating and wind [9]. If you have long-term constipation, talk to your doctor before you start taking fibre supplements: WGO notes that in some cases, for example with bowel obstruction or defecation disorders, a lot of fibre is not recommended [5].
Important: this information is about diet and lifestyle in general. It does not describe the effect of a fruttberry product and does not replace advice from a doctor.
When to see a doctor about constipation
Constipation usually improves once you change your habits. But there are signs that should always be checked by a doctor [1, 2, 6, 7, 10]. Don't try to “treat” them at home.
| Sign | What to do |
|---|---|
| Blood in your stool or on toilet paper | See your GP [1, 7] |
| Losing weight without trying | See your GP [1, 2] |
| A sudden, unusual change in bowel habits, especially if you are over 50 | See your GP [1, 6] |
| Symptoms lasting longer than 3 weeks or interfering with daily life | See your GP [7] |
| Constipation that keeps coming back or doesn't improve with lifestyle changes | See your GP [1] |
| Constant tiredness or frequent bloating as well | See your GP [1] |
| A family history of bowel or rectal cancer | Tell your doctor [2] |
| Constant or severe tummy pain, vomiting, fever, being unable to pass wind | Seek help right away [2] |
| Black or dark red stools, bloody diarrhoea | Get urgent medical help [10] |
| Bleeding from the back passage that won't stop | Call an ambulance (112 in the EU) [10] |
Also talk to a doctor if constipation affects a child or if you are pregnant. In these cases it's best to discuss diet changes and any supplements with a professional.
Fibre for every day: the fruttberry fibre blend
We created fruttberry out of a personal need: we wanted a fibre blend that we would actually enjoy drinking every day. If you don't get enough fibre from food, the blend can help you top up your daily intake.
Ingredients
- Psyllium husk (psyllium) is the base of the blend.
- Agave inulin is a soluble fibre that is fermented in the gut.
- Freeze-dried strawberries (12%) and blackcurrants (8%) give flavour and colour from real berries, not from flavourings.
- Glucomannan from konjac tubers is another soluble fibre.
How much fibre is in one teaspoon?
100 g of the blend contains 77 g of fibre. In an independent test by the KTU Food Institute, a sample of our blend contained as much as 84.4 g of fibre per 100 g. One teaspoon (5 g) provides about 3.86 g of fibre and just 11 kcal, so it's easy to work out how much it adds to your daily fibre intake. The blend contains no added sugar, gluten, lactose or preservatives, and it is suitable for vegans.
Stir one teaspoon into 200–250 ml of water and drink it straight away. Start with one teaspoon a day and increase the amount every 3–4 days. Remember to drink enough water throughout the day: psyllium and glucomannan swell, so taking them with too little liquid carries a risk of choking. If you have difficulty swallowing, don't take this type of fibre.
For home, the 250 g jar is the most convenient, and for work and travel there are 30 single servings of 5 g.
All fruttberry dietary fibre products in one place.
Frequently asked questions about constipation
How many days without a bowel movement counts as constipation?
There is no single number. The NHS says it's worth paying attention if you go fewer than 3 times a week or less often than usual [1]. Other signs matter too: hard stools, straining and a feeling of incomplete emptying.
What should you eat for constipation?
Health organisations advise choosing wholegrains, pulses, fruit, berries, vegetables, nuts and seeds more often, increasing fibre gradually and drinking more water at the same time [1, 3]. If the changes don't help within a few weeks, talk to your doctor.
Why does constipation often happen when travelling?
When you travel, your routine and food change, you drink less water, sit more and often have to put off going to the toilet [1, 2]. A water bottle within reach, fruit for snacks and keeping mealtimes as usual as possible all help.
Can more fibre make you bloated?
It can, especially if you increase it suddenly. That's why you should increase it slowly and drink enough fluids [9]. We write more about bloating in our article “Bloating: common causes and everyday habits”.
Can constipation be a sign of illness?
It is usually caused by lifestyle, but sometimes it is a sign of another condition [2]. If you also notice blood in your stool, weight loss, severe pain or a sudden change in bowel habits, especially if you are over 50, see a doctor [1, 6, 10].
Sources
- NHS. Constipation. Reviewed 2023.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Symptoms & Causes of Constipation. 2018.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Eating, Diet, & Nutrition for Constipation. 2018.
- Mearin F, Lacy BE, Chang L et al. Bowel Disorders. Gastroenterology. 2016;150(6):1393–1407.
- World Gastroenterology Organisation. A Global Cascade Approach to Diagnosis and Management of Chronic Constipation. WGO Global Guidelines, 2025.
- Lindberg G, Hamid SS, Malfertheiner P et al. World Gastroenterology Organisation global guideline: Constipation, a global perspective. Journal of Clinical Gastroenterology. 2011;45(6):483–487.
- Mayo Clinic. Constipation: Symptoms and causes. Accessed October 2026.
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on Dietary Reference Values for carbohydrates and dietary fibre. EFSA Journal. 2010;8(3):1462.
- British Dietetic Association. Fibre: Food Fact Sheet. 2021.
- NHS. Symptoms of bowel cancer. Reviewed 2026.
The information provided is general in nature and does not replace advice from a doctor or dietitian. The scientific data relate to fibre and diet in general and are not a description of the properties of a specific product. If you have a chronic condition, take medication, are pregnant or breastfeeding, talk to a healthcare professional before you start taking food supplements. Children should only take food supplements after consulting a doctor. A food supplement is not a substitute for a varied and balanced diet.
