What is irritable bowel syndrome?
Irritable bowel syndrome (IBS) is a chronic condition that affects the digestive system. It causes abdominal pain, constipation and diarrhoea. Symptoms of IBS can vary. There may be times when symptoms are problematic and other times when no symptoms are experienced at all. Although the symptoms of IBS are not associated with a serious threat to health they may have an effect on a person’s quality of life.
About 1 in 5 Australians experience IBS at some point in their lifetime.
What causes IBS?
The exact cause of IBS is unknown however most experts feel that it may be caused by a number of factors:
- an abnormal response to infection
- a problem with the immune system
- environmental, dietary and genetic factors that are still not known
- a symptom of another chronic condition such as fibromyalgia
- digestive organs that are sensitive to pain
- a malfunction with how muscles move food through the gut
There is also evidence that psychological factors may play a role in IBS, with changes to an emotional state during times of stress, anxiety and periods of depression triggering symptoms of IBS. When people go through periods of stress or anxiety it can cause chemical changes in the body and this can affect the digestive system making the symptoms of IBS worse. IBS is common in people who have suffered a previous traumatic incident.
Symptoms of IBS
- abdominal pain and cramping which may be relieved by emptying the bowels
- alteration in bowel habit such as diarrhoea, constipation or sometimes both
- excessive wind and abdominal bloating
- feeling of urgency when needing to go to the toilet to empty bowels (may result in incontinence if toilet is not immediately accessible)
- a feeling of not fully emptying the bowels
- passing mucous from the back passage
Diagnosis of IBS
A doctor will usually ask someone who describes symptoms of IBS to have a blood test. This is to rule out any condition which causes similar symptoms such as Coelaic Disease (a digestive disorder caused by gluten intolerance). Once other conditions are ruled out a doctor will usually diagnose IBS based on the person’s description of their symptoms.
The symptoms a doctor will usually be looking for are those which have been present for around six months such as changes in bowel habit (alternating between diarrhoea and constipation), abdominal pain and discomfort and bloating.
The doctor may ask about more specific symptoms that are very relevant to IBS such as abdominal pain that disappears once the bowels have been opened or abdominal pain with an accompanying change in bowel habit (e.g. needing to visit the toilet more frequently or stools which look different from usual).
For a doctor to diagnose IBS, a person needs to have two of the following symptoms:
- a change in bowel habit such as feeling a sense of urgency, needing to strain or a feeling of not fully emptying the bowels
- bloating or hardness of the abdomen
- symptoms that become worse after eating
- passing mucous from the back passage
Treatment of IBS
There is no known cure for IBS, but making changes to diet and lifestyle may help to reduce the frequency and intensity of symptoms.
Diet
Making changes to diet may help to control the symptoms of IBS. Keeping a food diary and noting foods which appear to trigger IBS can be a useful tool so these foods can be avoided. People with IBS are often advised to reduce the amount of fibre in their diet. For some people, this will mean reducing the amount of insoluble fibre (the type of fibre that makes stools bulkier and soft) consumed. This may mean reducing the consumption of wholemeal bread, cereals and whole grains such as brown rice.
Other dietary advice given to people with IBS includes:
- keep regular mealtimes
- avoid leaving long gaps between eating
- drink at least 8 glasses of water a day
- restrict caffeinated drinks to three per day
- limit intake of alcohol and carbonated drinks
- avoid processed and recooked food
- limit fresh fruit to three portions a day (a suitable portion would be an apple or half a grapefruit)
- to reduce the incidence of diarrhoea, avoid the artificial sweetener sorbitol which is found in sugar free sweets, chewing gum, some diet and diabetic products
- adding or increasing the amount of oats in a diet may help reduce wind and bloating
Probiotics
Some people find that taking probiotics (dietary supplements that contain so called ‘friendly bacteria’) reduce the symptoms of IBS. These supplements are available at most pharmacies and supermarkets and need to be taken for at least four weeks to see a result.
Exercise
30 minutes of strenuous exercise at least five times a week is advised to help reduce the symptoms of IBS. Exercise should be vigorous enough to increase heart rate and breathing rate, such as walking briskly.
Medication
There are a number of medications which can be used to treat the symptoms of IBS. These are:
- Antispasmodic medication
Antispasmodic medication acts by helping to relax the muscles of the digestive system. Medications include Mebeverine and therapeutic peppermint oil. Antispasmodic medication is not recommended for pregnant women.
- Laxatives
Laxatives are used to treat constipation. A bulk forming laxative is usually recommended for people with IBS related constipation. Bulk forming laxatives work by making stools softer and denser so that they become easier to pass. When starting a bulk forming laxative it is important to drink plenty of water in order to prevent the laxative from causing an obstruction in the gut. It is important to start on a low dose and increase the laxative slowly until one or two softly formed stools are passed every one to two days.
- Antimotility medication
Loperamide is used for the treatment of diarrhoea in IBS. It works by slowing down contractions of muscles in the gut which slows the speed at which food is passed through the intestines. This allows more time for stools to harden which helps to reduce diarrhoea. Loperamide is not suitable for pregnant women and may cause side effects such as abdominal cramps, dizziness, urinary retention, skin rash and bowel obstruction.
- Antidepressant medication
Tri-cyclic antidepressants work by relaxing the muscles of the digestive system and are usually recommended if antispasmodic mediations are not successful. Potential side effects include a dry mouth, drowsiness, constipation and fatigue. It is recommended that they are taken in the evening due to the potential side effect of drowsiness.
Cognitive behavioural therapy (CBT)
Cognitive behavioural therapy is a psychological intervention which can be effective for people with IBS. Studies into the effectiveness of CBT has shown that people who train themselves to cope differently with their condition by using relaxation techniques and maintaining a positive attitude often report a decrease in their level of pain. CBT can also help people cope with anxiety, stress and depression.
Support services
The Irritable Bowel Information & Support Association of Australia (IBIS) offers support and advice to those with IBS and their families: ibis-australia.org
