Irritable bowel syndrome (IBS)

Irritable bowel syndrome (IBS) is a common condition of the digestive system. It can cause bouts of stomach cramps, bloating, diarrhoea and constipation. The symptoms of IBS usually appear for the first time when a person is between 20 and 30 years of age. They tend to come and go in bouts, often during times of stress or after eating certain foods.

IBS may cause significant abdominal pains and cramps.

Symptoms vary between individuals and affect some people more severely than others. However, most people have either diarrhoea, constipation, or bouts of both. You may also have mucus in your stools. You may find the painful stomach cramps of IBS ease after going to the toilet and opening your bowels.


What causes IBS?

The exact cause of IBS is unknown, but most experts agree it's related to an increased sensitivity of the entire gut, which can occasionally be linked to a prior food-related illness. This may be caused by a change in your body's ability to move food through your digestive system, or may be due to you becoming more sensitive to pain from your gut. Psychological factors such as stress may also play a part in IBS.


When to see your doctor

You must visit your doctor if you think you have IBS. They will want to rule out other illnesses, such as an infection, coeliac disease (a digestive condition where a person has an adverse reaction to gluten) or chronic inflammation of the gut.

They will ask about your symptoms and whether there is a pattern to them – for example, if they tend to come on when you are under more stress than usual or after eating certain foods. Your doctor may suggest you keep a food diary to see whether your diet affects your symptoms. Further tests will only be needed if you have certain "red flag" symptoms that indicate you may have another serious condition. These symptoms include:
  • unexplained weight loss
  • a swelling or lump in your abdomen or back passage (bottom) 
  • anaemia (a lack of red blood cells).

Treating IBS

There is no cure for IBS, but the symptoms can be managed by making changes to your diet and lifestyle. Medication is sometimes prescribed for IBS. In many cases, being reassured by your doctor can often help control IBS symptoms. Although the symptoms of IBS can be troublesome, the condition does not pose a serious threat to your health. For example, it will not increase your chances of developing cancer or other bowel-related conditions.

IBS is unpredictable. You may go for many months without any symptoms and then have a sudden flare-up. It can also take many months for your symptoms to settle down. IBS can be painful and debilitating, and can have a negative impact on your quality of life. However, with appropriate treatment you should be able to live a normal, full and active life.

Flow chart showing the possible causes of IBS.


Living with IBS

The pain, discomfort and inconvenience of IBS can sometimes affect a person psychologically. It is estimated that three out of four people with IBS will have at least one bout of depression, and just over half will develop generalised anxiety disorder (a condition that can cause overwhelming feelings of anxiety, fear and dread).

Speak to your doctor if you have feelings of depression or anxiety and they are affecting your daily life. These types of conditions rarely improve without treatment, and your doctor will be able to recommend treatments such as antidepressants or cognitive behavioural therapy (CBT).

The exact cause of irritable bowel syndrome (IBS) is unknown, but most experts agree it is related to an increased sensitivity of the entire gut. This can be caused by:
  • a change in your body's ability to move food through your digestive system
  • becoming more sensitive to pain from your gut 
  • psychological factors
  • an episode of food poisoning.

Digestion process

Your body usually moves food through your digestive system by squeezing and relaxing the muscles of the intestines in a rhythmic way. However, in IBS it is thought this process is altered, resulting in food moving through your digestive system either too quickly or too slowly. Either way, there will be discomfort within the abdomen.

If food moves through your digestive system too quickly, you will have diarrhoea because your digestive system does not have enough time to absorb water from the food. If food moves through your digestive system too slowly, you will have constipation because too much water is absorbed, making your stools hard and difficult to pass.

It may be that food does not pass through the digestive systems of people with IBS properly because the signals that travel back and forth from the brain to the gut, controlling the nerves, are disrupted in some way. An increase in levels of a chemical called 5-hydroxytryptamine (5-HT), which can occur after eating certain foods or during times of stress, is also thought to affect the normal functioning of the gut.


Increased sensitivity

Many sensations in the body come from your digestive system. For example, nerves in your digestive system relay signals to your brain to let you know if you are hungry or full, or if you need to go to the toilet. Some experts think that people with IBS may be oversensitive to the digestive nerve signals. This means mild indigestion that is barely noticeable in most people becomes distressing abdominal pain in those with IBS.


Psychological factors

There is a fair amount of evidence to suggest psychological factors play an important role in IBS. However, this does not mean that IBS is "all in the mind", because symptoms are very real. Intense emotional states such as stress and anxiety can trigger chemical changes that interfere with the normal workings of the digestive system.

This does not just happen in people with IBS. Many people who have never had IBS before can have a sudden change in bowel habits when faced with a stressful situation, such as an important exam or job interview.

It has also been discovered that many people with IBS have experienced a traumatic event, usually during their childhood, such as abuse, neglect, a serious childhood illness or bereavement. It is possible that these types of difficult experiences in your past may make you more sensitive to stress and the symptoms of pain and discomfort.


IBS triggers

Certain foods and drinks can trigger the symptoms of IBS. Triggers vary from person to person, but the most common ones include:
  • alcohol 
  • fizzy drinks
  • chocolate
  • drinks that contain caffeine, such as tea, coffee or cola
  • processed snacks, such as crisps and biscuits
  • fatty food
  • fried food.

Keeping a food diary may be a useful way of identifying possible triggers in your diet. Stress is another common trigger of IBS symptoms. Therefore, finding ways to manage stressful situations is an important part of treating IBS.


Symptoms of IBS 

The symptoms of IBS are usually worse after eating and tend to come and go in bouts. Most people have a flare-up of symptoms that lasts two to four days. After this time, the symptoms usually improve but do not disappear completely. The most common symptoms of IBS are:
  • abdominal pain and cramping – often relieved by emptying your bowels
  • a change in your bowel habits – such as diarrhoea, constipation, or sometimes both
  • bloating and swelling of your abdomen
  • excessive wind (flatulence)
  • an urgent need to go to the toilet
  • a feeling that you need to open your bowels even if you have just been to the toilet
  • a feeling you have not fully emptied your bowels
  • passing mucus from your bottom. 

Due to the embarrassment, pain and discomfort of IBS, many people with the condition also have feelings of depression and anxiety.

Diagram summarising the main symptoms of IBS. 


Bowel symptoms

There are three main patterns of bowel symptoms in IBS. They are:
  • IBS with diarrhoea – when you have repeated bouts of diarrhoea
  • IBS with constipation – when you have repeated bouts of constipation
  • IBS mixed – when you have repeated bouts of diarrhoea and constipation.

These patterns are not set in stone. You can switch from one to another and go for long periods with few or no symptoms at all.


Diagnosing IBS 

There are no specific tests for IBS, as it does not cause any obvious detectable abnormalities in your digestive system. If you have the symptoms of IBS, your doctor will not always need to order blood tests to help diagnose you. However, in a few cases they may recommend blood tests to rule out other conditions that cause similar symptoms, such as an infection or coeliac disease (a stomach condition caused by gluten intolerance).

IBS is usually diagnosed by carrying out a physical examination and checking whether your symptoms match those typical of the condition. Your doctor will suspect you have IBS if one of the following criteria applies to you.
  • you have abdominal pain or bloating that is relieved when you pass a stool
  • you have abdominal pain or bloating associated with episodes of diarrhoea or constipation
  • you are passing stools more frequently than normal.

If you have at least two of the following symptoms, a diagnosis of IBS will be confirmed:
  • a change in how you pass stools, such as needing to strain, feeling a sense of urgency or feeling you have not emptied your bowels properly
  • bloating, hardness or tension in your abdomen
  • your symptoms get worse after eating
  • you pass mucus from your back passage.

Further tests

Further tests are usually only needed when you have certain "red flag" symptoms that indicate you may have another serious condition. These symptoms include:
  • unexplained weight loss
  • a swelling or lump in your abdomen or back passage
  • bleeding from your back passage
  • anaemia (a lack of red blood cells).

Further testing may also be recommended if you have a family history of bowel cancer or ovarian cancer, or if you are over 60 years of age and you have had a change in your bowel habits that has lasted for more than six weeks. Tests you may have include:
  • sigmoidoscopy – where a sigmoidoscope (a thin, flexible tube with a small camera and light at one end) is used to examine your back passage and the lower section of your bowel
  • colonoscopy – where a device similar to a sigmoidoscope, called a colonoscope, is used to examine your entire bowel.

Treating IBS 

The symptoms of irritable bowel syndrome (IBS) can often be reduced by changing your diet and lifestyle, and understanding the nature of the condition. In some cases, medication or psychological treatments may also be helpful.


IBS-friendly diet

Changing your diet will play an important part in controlling your symptoms of IBS. However, there is no "one size fits all" diet for people with IBS. The diet that will work best for you will depend on your symptoms and how you react to different foods. It may be helpful to keep a food diary and record whether certain foods make your symptoms better or worse. You can then avoid foods that trigger your symptoms. But it is important to remember these foods do not need to be avoided for life.


Fibre

People with IBS are often advised to modify the amount of fibre in their diet. There are two main types of fibre:
  • soluble fibre – which the body can digest
  • insoluble fibre – which the body cannot digest.

Foods that contain soluble fibre include:
  • oats
  • barley
  • rye
  • fruit, such as bananas and apples
  • root vegetables, such as carrots and potatoes
  • golden linseeds.

Bran is high in fibre.

Foods that contain insoluble fibre include:
  • wholegrain bread
  • bran
  • cereals
  • nuts and seeds (except golden linseeds).

If you have IBS with diarrhoea, you may find it helps to cut down on the insoluble fibre you eat. It may also help to avoid the skin, pith and pips from fruit and vegetables. If you have IBS with constipation, increasing the amount of soluble fibre in your diet and the amount of water you drink can help.

Your doctor will be able to advise you what your recommended fibre intake should be. The National Institute for Health and Clinical Excellence (NICE) provides more detailed advice about IBS and diet.


Eating tips

Your IBS symptoms may improve by following the advice below:
  • 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 and other non-caffeinated drinks such as herbal tea
  • restrict your tea and coffee intake to a maximum of three cups a day
  • lower the amount of alcohol and fizzy drinks you drink
  • reduce your intake of resistant starch, starch that resists digestion in the small intestine and reaches the large intestine intact – it is often found in processed or re-cooked foods
  • limit fresh fruit to three portions a day – a suitable portion would be half a grapefruit or an apple
  • if you have diarrhoea, avoid sorbitol, an artificial sweetener found in sugar-free sweets, including chewing gum and drinks, and in some diabetic and slimming products
  • if you have wind and bloating, consider stopping all cereals for six weeks or increasing your intake of linseeds (up to one tablespoon a day).

Avoid exclusion diets (where you do not eat a certain food groups, such as dairy products or red meat) unless you are being supervised by a professional dietitian.


Exercise

Most people find exercise helps relieve the symptoms of IBS. Your doctor will be able to advise you about the type of exercise that is suitable for you. Aim to do a minimum of 30 minutes vigorous exercise a day, at least three times a week. The exercise should be strenuous enough to increase your heart and breathing rates. Brisk walking and walking uphill are both examples of vigorous exercise.


Probiotics

Probiotics are dietary supplements that product manufacturers claim can help improve digestive health. They contain so-called "friendly bacteria" that supposedly destroy "bad bacteria", helping to keep your gut and digestive system healthy.

Some people find taking probiotics regularly helps relieve the symptoms of IBS. However, there is no scientific evidence to prove that probiotics work and have beneficial health effects. If you decide to try probiotics, make sure you follow the manufacturer's instructions and recommendations regarding dosage.


Reducing stress

Reducing the amount of stress in your life may help lower 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, pilates or tai chi  (where deep breathing and relaxation is combined with slow and gentle movements)
  • regular exercise, such as walking, running or swimming.

If you are particularly stressed, you may benefit from a talking therapy, such as stress counselling or cognitive behavioural therapy (CBT).


Medication

A number of different medications are used to help treat IBS, including:
  • antispasmodic medicines – which help reduce abdominal pain and cramping
  • laxatives – used to treat the symptoms of constipation
  • antimotility medicines – used to treat the symptoms of diarrhoea
  • antidepressants – originally designed to treat depression, but can also help reduce abdominal pain and cramping.

Antispasmodic medicines

Antispasmodic medicines work by helping relax the muscles in your digestive system. Examples of antispasmodic medicines include mebeverine and therapeutic peppermint oil. Side effects associated with antispasmodic medicines are rare. However, people taking peppermint oil may have occasional heartburn and irritation on the skin around their anus (bottom). Antispasmodic medicines are not recommended for pregnant women.

Antispasmotic medications may help improve the symptoms of IBS.

Laxatives

Bulk-forming laxatives are usually recommended for people with IBS-related constipation. They make your stools denser and softer, which means they are easier to pass. It is important you drink plenty of fluids while using a bulk-forming laxative. This will help prevent the laxative from causing an obstruction in your digestive system.

Start on a low dose and then, if necessary, increase it every few days until one or two soft stools are produced every one or two days. Do not take a bulk-forming laxative just before you go to bed. Side effects associated with taking laxatives can include bloating and wind. However, if you increase your dose gradually, you should have few, if any, side effects.


Antimotility medicines

The antimotility medicine loperamide is usually recommended for IBS-related diarrhoea. Loperamide works by slowing contractions of muscles in the bowel, which slows down the speed at which food passes through your digestive system. This allows more time for your stools to harden and solidify. Side effects of loperamide include:
  • abdominal cramps and bloating
  • dizziness
  • drowsiness
  • skin rashes.

Loperamide is not recommended for pregnant women.


Antidepressants

Two types of antidepressants are used to treat IBS – tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs). TCAs are usually recommended when antispasmodic medicines have not been able to control the symptoms of pain and cramping. They work by relaxing the muscles in your digestive system.

However, TCAs will only provide relief after three to four weeks, as your body starts to get used to the medication. They should be taken consistently. Possible side effects of TCAs include:
  • dry mouth
  • constipation
  • blurred vision
  • drowsiness.

These side effects should improve within a few days of starting the medication. You must tell your doctor if the side effects become a problem – they may prescribe another type of antidepressant. Amitriptyline is the most widely used TCA. Selective serotonin reuptake inhibitors (SSRIs) are an alternative antidepressant. Examples of SSRIs that are used to treat IBS include:
  • citalopram
  • fluoxetine
  • paroxetine.

Common side effects of SSRIs include blurred vision, diarrhoea or constipation and dizziness.


Psychological treatments

If your IBS symptoms are still causing problems after 12 months of treatment, your doctor may refer you for a type of therapy known as a psychological intervention. There are several different types of psychological therapy. They all work by teaching you techniques to help you control your condition better. The availability of psychological interventions on the NHS may vary from region to region.


Hypnotherapy

Hypnotherapy has been shown to help some people with IBS reduce their symptoms of pain and discomfort. Hypnosis is used to change your unconscious mind's attitude towards your symptoms. You can have hypnotherapy as an outpatient in some NHS hospital pain clinics, or you can learn self-hypnosis techniques to do at home.


Psychodynamic interpersonal therapy (PIT)

Psychodynamic interpersonal therapy (PIT) is a type of talking treatment that has had some success in helping people with IBS. It is a form of psychotherapy based on the principle that your unconscious thoughts, beliefs and attitudes can influence how you think, act and feel. Your therapist will help you to explore how your past might have unconsciously affected you. They will also help you to confront unhelpful beliefs, attitudes and behaviours in order to try to change them.


Cognitive behavioural therapy (CBT)

Cognitive behavioural therapy (CBT) is another type of talking treatment that can help with IBS. CBT is based on the principle that the way you feel depends partly on the way you think. Studies have shown that if you train yourself to react differently to IBS by using relaxation techniques and staying positive, you should see a decrease in your pain levels. CBT may also help you to cope better with stress, anxiety and depression.


Complementary therapies

Some people claim therapies such as acupuncture and reflexology can help people with IBS. However, there is no medical evidence to suggest they are effective and they are not recommended.


Complications

As irritable bowel syndrome (IBS) is not life-threatening, people who do not understand the condition are sometimes quick to trivialise it. However, the symptoms of IBS often have a significant impact on a person's day-to-day life. The pain, discomfort and inconvenience of IBS is very real and can have a deep psychological effect.

For example, it is estimated that three out of four people with IBS will have at least one episode of depression, and just over half will develop generalised anxiety disorder (GAD). This is a long-term condition that can cause feelings of unease, worry or fear. You should visit your physician if you are feeling anxious or depressed. These conditions rarely improve without treatment and they could make your IBS symptoms worse.


Your doctor will be able to recommend an effective treatment programme for you, such as antidepressants or cognitive behavioural therapy (CBT), or a combination of the two.

 Source: NHS Choices.