Causes of IBS

The exact cause of IBS is unknown. It's likely a combination of:

  • more frequent or stronger squeezing (contractions) of the muscles lining your bowel
  • increased sensitivity to the gas inside your bowel
  • your genetic make-up

Psychological factors, such as stress, may trigger your symptoms. Stress may result from work anxieties, exams, relationship difficulties, or life events such as divorce or bereavement.

Your symptoms may get worse after eating. Specific foods, such as tea, coffee and fatty foods, can also trigger symptoms.

Antibiotics and non-steroidal anti-inflammatory drugs, such as ibuprofen (eg Nurofen) and diclofenac (eg Voltarol), can make symptoms worse.

Symptoms of IBS

Most people with IBS find their symptoms an occasional nuisance but don't need to see a doctor. However, for some people the condition seriously affects their quality of life. If you find it difficult to cope with your symptoms, visit your doctor. People with IBS often continue to get symptoms from time to time.


The most common symptom of IBS is pain or discomfort in the abdomen. This may be associated with stomach cramps. The pain ranges from mild to severe, and may be made better by opening the bowels or passing wind. It is often made worse by eating.

Pain may occur at a particular time of day, often in the evening. Women often find the ups and downs of pain relates to their menstrual cycle.


Change in bowel habit

Your faeces may vary in consistency from hard and pellet-like to loose and watery. Alternatively, you may just pass small amounts of mucus. Your bowel movements may alternate between constipation and diarrhoea. At times, you may feel an urgent need to open your bowels or this may feel strained. Afterwards, you may feel that your bowels haven't been completely emptied.

IBS usually causes one symptom more than the others - either pain, constipation or chronic diarrhoea.

Other symptoms

Other symptoms that are sometimes present in IBS include:

  • excess wind
  • feeling sick
  • indigestion
  • backache
  • tiredness
  • fullness
  • bladder problems

These symptoms may be caused by problems other than IBS. You should visit your doctor for advice.

Diagnosis of IBS

Your doctor will ask about your symptoms and examine you. He or she may also ask about your medical history.

To make a diagnosis, your doctor will ask about your pain, when it comes on and what makes it better or worse. He or she may also ask about your bowel movements. They may ask how often you open your bowels, how easy it is to go and what your faeces look like. Your doctor may also ask you to have some blood tests.


If you have typical IBS symptoms and are under 50, it's unlikely you will need further tests. Your doctor may refer you for further tests if your symptoms may be linked to more serious bowel conditions. These include:

  • weight loss
  • blood in your faeces
  • symptoms first developing after age 60
  • a family history of bowel problems
  • diarrhoea without other symptoms
  • anaemia

Your doctor may refer you for a sigmoidoscopy or colonoscopy. This involves using an endoscope, a flexible, tube-like instrument, to look inside your bowel. He or she may take a biopsy (a small piece of tissue) from your bowel lining for examination in a laboratory. This test helps to rule out more serious conditions such as ulcerative colitis.

Other tests

If your doctor thinks that your IBS may be caused by an infection, you will be asked to give a sample of your faeces. This will be sent to a laboratory for tests. You may also need an X-ray of your abdomen such as a barium enema. In this test, a liquid containing a small amount of barium, a type of metal, is passed through a tube into your back passage where it enters the large intestine. The barium allows inflamed or ulcerated areas of the colon to show up clearly on X-ray images.

Treatment for IBS

Although there is no simple cure for IBS, there are treatments that can help reduce the symptoms. These include changes to your lifestyle, medicines and psychological treatments. With the help of your doctor, you can decide which is most suited to you.



Diet advice

For most people with IBS, a healthy lifestyle is the best way to improve symptoms. The following general advice about diet may help.

  • Eat regular meals.
  • Drink enough fluids. Limit caffeinated drinks, such as tea and coffee, alcohol and soft drinks.
  • Cut down on foods rich in insoluble fibre, such as wholemeal bread, wholegrain rice and cereals containing bran.
  • Eat no more than three portions of fruit a day.
  • Avoid processed foods. These may contain 'resistant starch' which is difficult for your body to digest.
  • If you have diarrhoea, cut out the artificial sweetener sorbitol. This is used in some sugar-free sweets and drinks, and diet products.
  • Try the supplement ispaghula powder to help relieve constipation.
  • Bloating symptoms may be improved by eating oats, which are found in some cereals and porridge, and a tablespoon of linseeds each day.

Other lifestyle advice

Regular exercise is a good way to help reduce your symptoms. It helps keep your bowel movements regular and reduces stress. If your symptoms are noticeably triggered by stress, try learning stress management or relaxation techniques. Keeping a diary to compare your symptoms with life events may also be helpful.

If you recognise that certain events trigger your symptoms, it may be easier to deal with the problem that is causing the symptoms. If these self-help treatments don't work, see your doctor for advice. He or she can help you identify factors that may be making your IBS worse, and suggest other treatments. If certain foods still seem to bring on your symptoms after trying this diet advice, seeing a dietitian may be helpful.


There are several over-the-counter medicines available from your pharmacist that can relieve some of the symptoms of IBS. These are listed below.

  • Anti-diarrhoea medicines, such as loperamide (eg Imodium) may help. You should only take them as needed, not on a regular basis.
  • Certain laxatives, such as ispaghula husk (eg Fybogel), can help if you have constipation. These are bulk-forming laxatives. Stronger laxatives called bowel-stimulating laxatives, such as senna, may help. However, you should speak to your doctor before using them routinely.
  • Antispasmodic medicines, such as mebeverine hydrochloride (eg Colofac), alverine citrate and peppermint oil capsules, may help with stomach cramps and wind.
  • Probiotics contain helpful bacteria and yeasts and are contained in some yoghurts. There is some scientific evidence that certain strains can be helpful for IBS symptoms, but this isn't conclusive.
  • If you need to use painkillers, ibuprofen (eg Nurofen) or aspirin may make your symptoms worse. Try to use paracetamol. 

Always read the patient information that comes with your medicine and if you have any questions, ask your pharmacist for advice. 

Your doctor may prescribe medicines for IBS. These include prescription-only versions of the medicines mentioned above. Low-dose antidepressants can reduce the pain of IBS, even if you're not depressed. 

If your symptoms don't improve after a year of treatment, your doctor may consider psychological therapies. 

Talking treatments such as cognitive behavioural therapy, hypnotherapy or psychotherapy can help relieve the symptoms. These may be most useful for people who have personal difficulties to deal with. Your doctor may refer you to a suitable therapist.


click here to learn more to about G-NiiB Immunity+ Microbiome Precision Formula
Last Updated: Aug 2017
Please note that all medical health articles featured on our website have been reviewed by Quality Healthcare doctors. The articles are for general information only and are not medical opinions nor should the contents be used to replace the need for personal consultation with a qualified health professional on the reader’s medical condition.