Overactivity of the nerves or muscles of the gut. It is not known why this may occur. It may have something to do with overactivity of messages sent from the brain to the gut. Stress or emotional upset may play a role. About half of people with IBS can relate the start of symptoms to a stressful event in their life. Symptoms tend to become worse during times of stress or anxiety.
Intolerance to certain foods may play a part in some cases. However, this is thought to be only in a small number of cases.
Infection and bacteria in the gut. IBS is not caused by an ongoing gut infection. However, in about 1 in 6 cases, the onset of symptoms seems to follow a bout of gastroenteritis (a gut infection which can cause diarrhoea and vomiting). So, perhaps a virus or other germ may 'sensitise' or 'trigger' the gut in some way to cause persisting symptoms of IBS.
Also, in some cases, symptoms get worse after taking a course of antibiotics. Antibiotics kill certain harmless bacteria in the gut which changes the balance of bacteria types in the gut.
What are the treatments for irritable bowel syndrome?
Many people are reassured that their condition is IBS, and not something more serious such as colitis. Simply understanding about IBS may help you to be less anxious about the condition, which may ease the severity of symptoms. Symptoms often settle for long periods without any treatment. In some cases, symptoms are mild and do not require treatment.
If symptoms are more troublesome or frequent, one or more of the following may help.
Foods, drinks and lifestyle
Some people with IBS find that one or more foods can trigger symptoms, or make symptoms worse ('food intolerance or sensitivity'). A food intolerance is more common in people with IBS who have diarrhoea as a main symptom. If you are not sure if a food is causing symptoms, it may be worth trying a bland diet if symptoms are difficult to control. For example, one meat, one fruit, and one vegetable. (Ideally, this is best done under the supervision of a dietician.) Then, add in different foods gradually to your diet to see if any cause the symptoms. It may be possible to identify one or more foods that cause symptoms. This can be a tedious process, and often no problem food is found. However, some people say that they can control their symptoms by identifying one or more foods that cause symptoms, and then not eating them.
The foods that are most commonly reported to cause IBS symptoms in the UK are: wheat (in bread and cereals), rye, barley, dairy products, coffee (and other caffeine-rich drinks such as tea and cola), and onions.
Some people report an improvement in symptoms when they cut down from drinking a lot of alcohol, or stop smoking if they smoke. Regular exercise may also help to ease symptoms. Stress and other emotional factors may trigger symptoms in some people.
It may help to keep a food and lifestyle diary for 2-4 weeks to monitor symptoms and activities. Note everything that you eat and drink, times that you were stressed, and when you took any formal exercise. This may identify triggers, such as a food, alcohol, or emotional stresses, and may show if exercise helps to ease or prevent symptoms.
Treating constipation
Constipation is sometimes a main symptom of IBS. If so, it often helps to eat foods with plenty of fibre, and to drink plenty (two litres of fluids per day or more - to keep the stools moist). Fibre (roughage) is the part of the food which is not absorbed into the body. It remains in your gut, and is a main part of the stools. You can eat plenty of fibre by eating plenty of fruit, vegetables, cereals, fruit juice, wholemeal bread, etc. Another leaflet called 'Fibre in the Diet' gives more details.
If increasing 'fibre and fluids' does not ease constipation then bulk-forming laxatives (sometimes called fibre supplements) can help. These increase the 'bulk' of your faeces and are not 'medicines' as such. Unprocessed bran is the cheapest. You can sprinkle bran on breakfast cereals, or mix it with fruit juices, stews, soups, yoghurts, crumbles, scones, etc. Alternatives are ispaghula husk, methylcellulose and sterculia. You can buy these from pharmacies and health food shops, or get them on prescription. Their full effect may take some days to develop.
A note of caution: fibre and bulk-forming laxatives partly work by absorbing water (a bit like blotting paper). The combination of plenty of fibre or bulk-forming laxatives and fluid produces soft, bulky stools which should be easy to pass out when you go to the toilet. When you eat a high fibre diet, or take bulk-forming laxatives, you should drink plenty. At least two litres per day (8-10 cups). The faeces may become dry and difficult to pass out if you do not have enough to drink. Very rarely, lots of fibre or bulk-forming laxatives and not enough fluid causes an obstruction in the gut.
Note: fibre or bulk-forming laxatives do not usually help with other symptoms of IBS such as pain or bloating. Also, in some people with IBS, especially those with diarrhoea, extra fibre or bulk-forming laxatives makes symptoms worse (particularly bloating). So, it may not be such a good idea to increase fibre or take bulk-forming laxatives if you are not constipated.
Sometimes other types of laxatives are advised for short periods if the measures above are not enough to ease a troublesome bout of constipation.
Treating diarrhoea
An antidiarrhoea medicine may be useful if diarrhoea is a main symptom. Loperamide is the most commonly used antidiarrhoea medicine for IBS. You can buy this at pharmacies (but it is quite expensive). You can also get it on prescription which may be more cost effective if you need to take it regularly.
The dose of loperamide needed to control diarrhoea varies considerably. Many people use loperamide 'as required' but some take it regularly. Many people learn to take a dose of loperamide in advance when they feel diarrhoea is likely to be a problem. For example, before going out to places where they know it may be difficult to find a toilet.
Antispasmodic medicines
These are medicines that relax the muscles in the wall of the gut. Your doctor may advise one if you have spasm-type pains. There are several types of antispasmodics, and they work in slightly different ways. Therefore, if one does not work well, it is worth trying a different one. If one is found to help, then you can take it 'as required' when pain symptoms flare-up. Many people take an antispasmodic medicine for a week or so at a time to control pain when bouts of pain flare-up. Some people take a dose before meals if pains tend to develop after eating. Note: pains may ease with medication but may not go away completely.
Antidepressant medicines
An antidepressant medicine in the 'tricyclic' group is sometimes used to treat IBS. In particular, it tends to work best if pain and diarrhoea are the main symptoms. (Tricyclic antidepressants have other actions separate to their action on depression. They are used in a variety of painful conditions, including IBS.) Unlike antispasmodics, you need to take an antidepressant regularly rather than 'as required'. Therefore, an antidepressant is usually only advised if you have persistent symptoms, or frequent bad flare-ups that have not been helped by other treatments.
Psychological treatments (talking treatments)
Situations such as family problems, work stress, exams, recurring thoughts of previous abuse, etc, may trigger symptoms of IBS in some people. People with anxious personalities may find symptoms difficult to control. The relationship between the mind, brain, nervous impulses, and overactivity of internal organs such as the gut is complex. Some people have found such things as relaxation techniques, stress counselling, cognitive behaviour therapy, psychotherapy, hypnotherapy, and similar therapies useful in controlling symptoms of IBS.
Psychological treatments are generally mainly considered in people with moderate to severe IBS, when other treatments have failed, or when it seems that stress or psychological factors are contributing to causing symptoms. However, some of these treatments may not be available on the NHS in your area, or there may be long waiting lists.
Other treatments
Various alternative and complimentary therapies are sometimes used. For example, studies have shown that certain chinese herbal medicines, and probiotics such as Lactobacillus plantarum LP01 and Bifidocterium breve BR0 may help to ease symptoms in some cases. However, more research is needed to clarify their role and usefulness.
Newer medicines that affect certain functions of the gut are also being developed and may become useful treatments in the future.
What is the outlook (prognosis)?
In most people with IBS, the condition tends to persist long-term. However, the severity of symptoms tends to 'wax and wane' and you may have long spells without any symptoms, or with only mild symptoms. Treatment can often help to ease symptoms when they flare-up. In a minority of cases, symptoms clear for good at some stage.
IBS does not shorten your expected life span, it does not lead to cancer of the bowel, and does not cause blockages of the gut or other serious conditions.
Further help and advice
The Gut Trust
Tel: 0114 272 32 53
Web: www.theguttrust.org
Offers advice, information and support for people with IBS.
References
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Guidelines for the management of the irritable bowel syndrome, British Society of Gastroenterology (2000)
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© EMIS and PiP 2007 Updated: 20 Nov 2007 DocID: 4286 Version: 38
