Irritable Bowel Syndrome (IBS) – A Guide

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Irritable bowel syndrome (IBS) is a chronic (long-term) disorder that affects the digestive system. It causes abdominal pain, diarrhoea and constipation.

Symptoms of IBS
Causes of IBS
Diagnosing IBS
Treating IBS
Complications of IBS


There are different types of IBS, depending on your main symptom. It’s known by a variety of other names, including spastic colon, spastic colitis, mucous colitis, nervous diarrhoea, nervous colon and nervous or functional bowel. However, some of these names misrepresent the condition. Colitis, for example, is an inflammation of the colon and this symptom isn’t found in people with IBS.

The symptoms of IBS can fluctuate. There may be times when your symptoms are particularly troublesome and times when you experience no symptoms at all.

Although IBS poses no serious threat to health, it can have an adverse effect on a person’s quality of life. The exact causes of IBS are unknown.

How common is IBS:

IBS is one of the most common gastrointestinal conditions. It is estimated that 10-20% of the UK’s population is affected by IBS at any one time, although this figure may be higher because many people with the condition do not report their symptoms to their GP.

IBS is twice as common in women as it is in men. The condition normally develops in people who are between 20 and 30 years of age, but it can affect people of any age.

While there is no cure for IBS, the symptoms can be controlled with lifestyle changes and medicine.

Symptoms of IBS

The most common symptoms of irritable bowel syndrome (IBS) are:

  • abdominal pain and cramping which is often relieved by emptying your bowel,
  • a change in your bowel habits, such as diarrhoea, constipation or, sometimes, both,
  • bloating and swelling of your abdomen,
  • excessive wind,
  • experiencing an urgent need to go to the toilet, which can result in incontinence if a toilet is not nearby,
  • a feeling that you have not fully emptied your bowel, and
  • the passing of mucus from your rectum (back passage).

The symptoms of IBS are usually worse after eating. Most people will experience a ‘flare-up’ of symptoms, lasting between 2-4 days, after which the symptoms improve, or disappear altogether.

For reasons that are not completely understood, IBS can also cause symptoms in other parts of your body, as well as in your bowel. These symptoms include:

  • lower back pain,
  • muscle and joint pain,
  • constant tiredness,
  • nausea,
  • headache,
  • burping,
  • bad breath, and
  • a frequent and urgent need to urinate.

Due to the pain, discomfort and embarrassment that are sometimes associated with IBS, some people also experience feelings of anxiety and depression.

Irritable Bowel Solutions: The essential guide to IBS, its causes and treatments

Irritable Bowel Syndrome IBS (Understanding) (Family Doctor Books)

Irritable Bowel Syndrome and Diverticulosis: A Self-Help Plan

Causes of IBS:

The exact cause of irritable bowel syndrome (IBS) is unknown. However, most experts believe that it may be caused by a number of interrelated factors. Possible factors include:

  • an abnormality with how the muscles move food through the digestive tract,
  • having digestive organs that are particularly sensitive to pain,
  • a malfunctioning immune system,
  • a problem with how the central nervous system controls the digestive system,
  • an unusual response to infection, and
  • environmental, dietary, and genetic factors that are as yet unknown.

Psychological factors in IBS

There is a great deal of evidence that psychological factors play an important role in IBS. This is not to suggest that IBS is ‘all in the mind’ because the symptoms people experience are very real.

Changes in emotional states, such as stress, or depression, often cause a flare-up of symptoms. IBS is also more common in people who have experienced a previous traumatic experience.

How you think and feel can have an important effect on your body. When you are feeling stressed, or depressed, your body undergoes chemical changes and it is possible that these changes can affect how your digestive system works, making the symptoms of IBS worse.

This is why psychological treatments, such as relaxation therapy, are often effective in helping to control the symptoms of IBS.

Diagnosing IBS:

Although the symptoms of IBS can be similar to those seen in more serious conditions, once it has been diagnosed there’s no reason to think that it will develop into anything more sinister. In particular, people with IBS are no more likely than anyone else to develop bowel cancer.

If you have the symptoms of irritable bowel syndrome (IBS), your GP will usually recommend that you undergo a blood test in order that other conditions that cause similar symptoms, such as infection, or Coeliac disease (a stomach condition caused by gluten intolerance) can be ruled out.

GPs can usually confidently diagnose IBS by asking you about your symptoms.

Your GP will ask you whether you have had any of the following symptoms that have lasted for at least six months:

  • changes in your bowel habits, such as constipation, or diarrhoea,
  • pain and discomfort in your abdomen, and
  • a bloated feeling.

Your GP will be looking for some specific symptoms that are needed for a positive diagnosis of IBS. These are either:

  • abdominal pain, or discomfort, that goes away after you empty your bowel, or
  • abdominal pain, or discomfort, with a change in your bowel habits – for example, you may go to toilet more often than you did before, or you may produce stools that look different from usual.

For IBS to be diagnosed, you will also need to have at least two of the following symptoms:

  • a change in how you pass stools, such as needing to strain, feeling a sense of urgency, or feeling that you have not emptied your bowels properly,
  • bloating, hardness or tension in your abdomen,
  • symptoms that are worse after eating, or
  • the passing of mucus from your rectum (back passage).

When further tests are required

Further testing is usually only required when you have specific symptoms, or signs, that suggest that you may have a more serious condition than IBS. These symptoms include:

  • unexplained weight loss,
  • abdominal and rectal mass (localised swelling in the abdomen and/or rectum),
  • bleeding from your rectum (back passage), and
  • anaemia (a condition that occurs when there is a reduced number of red blood cells, or haemoglobin concentration in the blood).

Further testing may also be recommended if you have a family history of bowel, or ovarian, cancer, or if you are over 60 years of age and you have experienced a change in your bowel habits that has lasted more than six weeks.

Treating IBS:


Making changes to your diet can help to control the symptoms of irritable bowel syndrome (IBS). However, there is no ‘one size fits all’ diet for people with IBS. Different individuals will respond better to individually tailored diets.

Keeping a food diary and making a note of whether certain foods make the condition better, or worse, may be helpful. Once you have identified any ‘trigger foods’ you can avoid them.

People with IBS are often advised to modify the amount of fibre in their diet. For some people, this will be a case of reducing the amount of insoluble fibre (the type that make stools bulkier and soft) in their diet. This may mean reducing your consumption of wholemeal bread, cereals and whole grains, such as brown rice.

Other people with IBS may need additional fibre in their diet, usually soluble fibre. This may mean taking a fibre supplement, or eating more foods that are high in soluble fibre, such as oats.

Your GP will be able to advise you about what your recommended fibre intake should be. The dietary advice listed below may also help you to control your symptoms of IBS.

  • Have regular meals, and take your time when eating.
  • Avoid missing meals, or leaving long gaps between eating.
  • Drink at least eight cups of fluid a day, particularly water, or other non-caffeinated drinks, such as herbal teas.
  • Restrict tea and coffee to three cups a day.
  • Reduce your intake of alcohol and fizzy drinks.
  • Reduce your intake of ‘resistant starch’ (starch that resists digestion in the small intestine and reaches the colon intact). It is often found in processed, or recooked, foods.
  • Limit fresh fruit to three portions (80 g each) a day; a suitable portion would be half a grapefruit, or one apple.
  • If you have diarrhoea, avoid sorbitol, which is an artificial sweetener that is found in sugar-free sweets (including chewing gum) and drinks, and in some diabetic and slimming products.
  • If you have wind and bloating, consider increasing your intake of oats, for example, oat-based breakfast cereal, or porridge, and linseeds (up to one tablespoon a day).

Do not undertake a single food avoidance and exclusion diet (a diet where you avoid a class of food, such as dairy products, or red meat) unless you are under the supervision of a dietitian.


Exercise can help to relieve the symptoms of most (but not all) people with IBS. However, regular exercise has many associated health benefits and should form part of your daily and weekly routine regardless of whether you have IBS or not. Your GP will be able to advise you about whether exercise is suitable for you.

If exercise is suitable for you, you should aim for a minimum of 30 minutes of vigorous exercise a day, at least five times a week. The exercise should be strenuous enough to increase both your heart rate and breathing rate. Walking briskly and walking up a hill are both examples of vigorous exercise.


Some people find that taking probiotics helps to relieve the symptoms of IBS. Probiotics are dietary supplements that contain so-called ‘friendly bacteria’, and are available at most supermarkets.

You will need to take probiotics for at least four weeks to see if they have a beneficial effect. When taking it, make sure that you follow the manufacturer’s instructions and recommendations.

The use of prebiotics – dietary supplements that encourage the growth of certain types of bacteria in the intestine – is not recommended as a treatment for IBS.


Taking steps to reduce the levels of stress in your life may help to reduce the frequency and severity of your IBS symptoms.

Some ways to help relieve stress include:

  • relaxation techniques, such as meditation, or breathing exercises,
  • physical activities, such as yoga, or Tai Chi (a Chinese martial art), and
  • regular exercise.

If you are finding that stress is a problem in your life, you may benefit from a talking therapy, such as stress counselling, or cognitive behaviour therapy (CBT). See below for more information about CBT.


A number of different medications are used to help treat IBS. These are.

  • Antispasmodic medicines, which help to reduce abdominal pain and cramping,
  • Laxatives, which help to treat the symptoms of constipation,
  • Antimotility medicines, which help to treat the symptoms of diarrhoea, and
  • Tricyclic antidepressants (TCAs), which were originally designed to treat depression, but also help to reduce the feeling of abdominal pain and cramping.

See below for more information on these medications.

There is also a medicine called Kolanticon, which contains an antispasmodic drug and three other ingredients. The other ingredients are simeticone, which relieves trapped wind, and two different antacids, which reduce stomach acid and treat heartburn. Kolanticon is available from your pharmacy without prescription.

Antispasmodic medicines

Antispasmodic medicines work by helping to relax the muscles in your digestive system. Examples of antispasmodic medicines include mebeverine and therapeutic peppermint oil.

Side effects of antispasmodic medicines are uncommon. However, people taking peppermint oil can sometimes experience occasional heartburn and irritation on the area of skin around their anus.

Antispasmodic medicines are not recommended for use by pregnant women.


The type of laxative known as a bulk-forming laxative is usually recommended for people who are experiencing IBS-related constipation. Bulk-forming laxatives work by making your stools (faeces) denser and softer, which means that they should be easier to pass.

It is important to drink plenty of fluids when using a bulk-forming laxative because this will prevent the laxative causing an obstruction in your digestive system.

You should start on a low dose, and if necessary increase it every few days until one or two soft, formed stools are produced every one or two days. You should not take a bulk-forming laxative immediately before going to bed.

Side effects of taking laxatives can include bloating and flatulence (wind). However, side effects can usually be avoided or reduced by gradually increasing the dose.

Antimotility medicines

The antimotility medicine known as loperamide is usually recommended for the treatment of IBS-related diarrhoea. Loperamide works by slowing the contractions of the muscles in the intestines which, in turn, slows how fast food passes through your digestive system. This allows more time for your stools to harden and solidify.

Side effects of loperamide include:

  • abdominal cramps,
  • dizziness,
  • drowsiness,
  • skin rashes,
  • bowel obstruction, and
  • abdominal bloating.

Loperamide is not recommended for use by pregnant women.

Tricyclic antidepressants (TCAs)

Tricyclic antidepressants (TCAs) are usually recommended if antispasmodic medicines have failed to control your symptoms of abdominal pain and cramping. TCAs work by relaxing the muscles in your digestive system.

Side effects of TCAs include:

  • constipation,
  • dry mouth,
  • drowsiness, and
  • fatigue.

Due to their potential to cause drowsiness and fatigue, you may be advised to take TCAs before going to bed. You should not drive, or operate heavy machinery, if you are experiencing drowsiness.

If you fail to respond to TCAs, an alternative antidepressant, known as a selective serotonin reuptake inhibitor (SSRI) may be recommended for you.

Complementary therapies

A number of complementary therapies for IBS have been suggested including:

  • acupuncture,
  • reflexology (a type of massage therapy), and
  • the herbal remedy aloe vera (a plant that is native to north Africa).

However, there is no evidence that these complementary therapies are effective at treating IBS. You should also be aware that aloe vera has been linked to a number of possible adverse effects, such as dehydration and a reduction in blood sugar levels.

Psychological interventions

If your symptoms of IBS are still causing you problems after 12 months of treatment, you may be referred for a type of therapy known as a psychological intervention.

There are several types of interventions available, but they all work by teaching you psychological techniques that can help you to control your condition more effectively.

Psychodynamic interpersonal therapy (PIT)

Psychodynamic interpersonal therapy (PIT) is a type of psychotherapy that has had some success in helping people with IBS. PIT is based on the principle that your unconscious thoughts, beliefs and attitudes can have an important influence on the way that you think, act, and feel.

During PIT, your therapist will help you to explore your past in order to determine how it might have affected you unconsciously, and they will help you to confront unwelcome, or unhelpful beliefs, attitudes, and behaviour in an attempt to change them.


Psychological interventions for IBS include hypnotherapy. In this type of therapy, hypnosis is used to change your unconscious mind’s attitude towards any symptoms that you may have. You may also be taught self-hypnosis techniques.

Hypnotherapy has been shown to be effective in helping some people reduce their symptoms of pain and discomfort.

Cognitive behavioural therapy (CBT)

Another psychological intervention for IBS is cognitive behavioural therapy (CBT). CBT is based on the principle that the way that we feel is partly dependent on the way that we think about things.

Studies into the effectiveness of CBT have shown that people who train themselves to react differently to their condition by using relaxation techniques and maintaining a positive attitude, report a decrease in pain levels.

CBT may also help you to cope better with stress, anxiety and depression.

Complications of IBS

Access to toilet facilities

Finding access to toilets can be an important issue if you are experiencing symptoms of sudden and urgent diarrhoea. In the most severe cases of irritable bowel syndrome (IBS), some people are afraid to visit public places in case they experience an episode of incontinence.

There are a number of steps that you can take to help you deal with the problem. For example, the IBS charity, ‘The Gut Trust’ operates a ‘Can’t Wait’ card scheme. This is a small card, confirming that you have a medical condition which indicates that you may require immediate access to toilet facilities. Should you need to, you can use the card to gain access to the toilet facilities of businesses, supermarkets, or other organisations.

Another alternative is to join the National Key Scheme. The National Key Scheme (NKS) offers independent access to people with certain health conditions, such as IBS, to around 7,000 locked public toilets around the country.

Psychological impact

As IBS is not a life-threatening condition, it is sometimes trivialised it as beingnothing more that a form of indigestion. However, the pain, discomfort, and inconvenience caused by IBS can have a profound psychological affect on the individual.

It is estimated that the majority of people with moderate to severe IBS will experience feelings of depression and anxiety at some point in their life.

If you find that you have been feeling particularly down over the past month, and you no longer take pleasure in the things that you used to enjoy, you may be depressed. You should see your GP for advice and treatment.

Cognitive behavioural therapy (CBT) may also help you cope better with your condition and any feelings of depression and anxiety that you have.

You may also want to consider joining an IBS support group because talking to people who share your condition can reduce feelings of loneliness, isolation, and stress. Your GP may be able to provide details of support groups in your local area.