Irritable bowel syndrome (IBS) (2024)

We take a look at the symptoms, causes and treatments of irritable bowel syndrome.

Irritable bowel syndrome (otherwise known as IBS) is a condition that causes recurring pain or discomfort in the abdomen—that area below your chest and above your hips.

If you’re dealing with IBS, you’re certainly not alone. IBS is super common, with about one in five Australians (women twice as likely as men) having symptoms of IBS at some point in their lifetime, often starting in early adulthood. It’s also among the most common complaints presenting to GPs.

About IBS

Digestive issues are never fun, but IBS is one of the most common problems of the digestive system, typically causing abdominal pain, bloating, constipation or diarrhoea.

IBS is what’s known as a functional bowel disorder. This means that although there’s a change in how your gut functions, there’s no obvious structural change when it’s examined, via biopsies and X-rays for example. It’s easy to get confused with IBS and IBD (they both affect the same regions, after all), but they’re completely different. IBD, AKA Inflammatory Bowel Disease, is a term covering Crohn’s disease and ulcerative colitis.

Symptoms of IBS

IBS is a chronic and often unpredictable condition. Some may find their IBS symptoms an occasional nuisance, but for others the condition seriously affects their quality of life, causing stress and anxiety. The symptoms are seriously the pits and can be painful and can even change over time. Bowel issues aren’t always the easiest to talk about either, but if you’re struggling with your symptoms, it’s a good idea to go and chat to your GP for some advice. Let’s take a look at the symptoms.

Pain and bowel changes

The most common symptoms of IBS are abdominal pain or discomfort, such as stomach cramps, combined with a change in bowel habits. Things can go from mild to severe, with the pain often described as sharp, dull, crampy, gas-like or a generalised ache. It may improve or be made worse by opening the bowels or passing wind—and often made worse by eating.

When is the pain likely to occur? Many people report feeling it at a particular time of day, often in the evening. And for some women, they often find the ups and downs of pain falling parallel with their menstrual cycle. Coincidence? Perhaps not.

Sure, everyone experiences bowel changes from time to time. But IBS is a little different, with symptoms being more severe and most likely to occur more often. Your stools may vary in consistency from hard and pellet-like (constipation) to loose and watery (diarrhoea). Alternatively, you may just pass small amounts of mucus. At times, you may feel an urgent need to open your bowels, or it could even feel strained. Afterwards, you may feel that your bowels haven't been completely emptied.

Often, one IBS symptom will recur more often than the others—either pain, constipation or chronic diarrhoea. But don’t be surprised if you have more than one symptom at once.

Abdominal bloating and gas

Causes of IBS

The exact cause of IBS isn’t so clear cut and can vary from person to person, although there are several theories including psychological stress or a bout of food poisoning or gastroenteritis. In all likelihood, it’s probably a combination of:

more frequent or stronger squeezing (contractions) of the muscles lining your bowel, or weaker intestinal contractions that slow food passage
increased sensitivity to signals coming from your gut
inflammation in the intestines caused by an increased number of immune-system cells
improper functioning of the immune system (over or under active)
changes in the gut bacteria (microflora)
genetics.

Many people with IBS feel that their symptoms often arise from psychosocial factors, often indicating how they feel about what’s going on in their lives. Emotional stress always seems to make symptoms worse, whether it’s from work anxieties, exams, relationship difficulties, or life events such as divorce or bereavement.

Symptoms may get worse after eating specific foods and drinks, such as tea, coffee, alcohol, and fatty foods, for example. Garlic and onions can often trigger symptoms as they are very high in FODMAPs (see below). Hormones may play a role, as many women find that symptoms are worse during or around their menstrual period. Antibiotics and non-steroidal anti-inflammatory medicines, such as ibuprofen and diclofenac, can also make symptoms worse.

The Gut Brain Axis

Ever felt butterflies in your tummy? That’s your Gut-Brain Axis in action. The Gut-Brain Axis is a communication system between your digestive tract and brain. It’s bi-directional, which means the brain communicates with the gut, and the gut also communicates information to your brain.

The Gut-Brain Axis may play an important role in IBS. When it’s out of balance your gut may become more sensitive than normal and you may experience normal gut sensations, such as food moving through the digestive tract, as unpleasant or painful.

Diagnosis of IBS

Don’t be tempted to self-diagnose IBS. Other conditions, such as coeliac disease, Crohn’s disease, ulcerative colitis and endometriosis, have similar symptoms. So, it’s always a good idea to see your GP to rule out other possible diagnoses.

After investigating your medical history, your GP will ask about your symptoms such as when your pain comes on, what makes it better or worse, how often you open your bowels, and whether you experience diarrhoea or constipation. Unfortunately, there's no test that can confirm IBS, but your GP may order tests to eliminate other conditions, particularly if you have any of these symptoms:

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

Other tests

If your GP thinks your IBS may be caused by an infection, you’ll be asked to give a stool sample. This will be sent to a laboratory for tests. You may also need an X-ray of your abdomen, a procedure called a barium enema.

Treatment of 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 GP, you can decide which is most suited to you.

Education about IBS and good self-management can make a huge difference to the symptoms you experience. For some people, simple diet and lifestyle modifications may be all that’s needed to relieve symptoms. Once you know your own personal triggers—whether it be foods, components in foods or stress—there are things you can do to take control and ease your symptoms.

Diet advice

For many people with IBS, a healthy lifestyle can improve symptoms. We’ve compiled a list of general diet advice that might help:

Eat regular, smaller meals and snacks.
Eat until you feel full and not more.
Drink plenty of water or non-caffeinated fluids.
Limit soft drinks as well as caffeinated drinks such as tea, coffee and energy drinks.
Limit alcohol to no more than 10 standard drinks per week, and no more than 4 on any one day.
Limit intake of spicy, rich and fatty foods, or other foods you’ve identified as triggers, such as garlic and onions. You may find keeping a food diary can help identify which foods may cause your symptoms.

Management of diarrhoea

Reduce sugar-free or diet products that contain sorbitol, mannitol or xylitol. These are used in some sugar-free sweets and drinks as well as diet products, and can have a laxative effect.
Replace lost fluid by drinking enough throughout the day.
If you experience wind and bloating, reduce gas-producing foods such as beans, pulses, Brussels sprouts, cauliflower and sugar-free mints/chewing gum. Add a tablespoon of linseeds every day to other foods such as yoghurt, porridge and salads.
Some people report improvement in diarrhoea if they stop eating gluten (found in wheat, barley and rye) even if they don’t have coeliac disease.

Management of constipation

Make sure you have adequate fluids.
Include a wide variety of high fibre foods. These can include oats, oat bran, brown rice, wholemeal or wholegrain bread and pasta, potatoes with skin, quinoa, fruit and vegetables. You may find that soluble fibres such as psyllium and oats improve your symptoms more than insoluble fibre such as wheat grain and wholewheat flour.

The low FODMAP diet

Researchers from Melbourne’s Monash University have found that eating a diet that is low in certain carbohydrates (sugars) helped to alleviate symptoms in 75% of the IBS patients they treated.

These carbohydrates are called FODMAPs (an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols), and are essentially molecules in foods that aren’t easily digested and absorbed by some people with IBS symptoms.

A low FODMAP diet is increasingly being used in the treatment of IBS, but it must be done under the care and guidance of an Accredited Practising Dietitian. It’s also not advised to remain on it for long as it can change the balance of your gut microbiome to one that’s unfavourable. Expect to try it for a short time before foods are gradually re-introduced to see which ones trigger a flare-up of symptoms. Fortunately, it’s unlikely you’ll be sensitive to all FODMAPs so you may be able to re-introduce some of your favourite foods.

Other lifestyle advice

Regular exercise is a good way to help reduce your symptoms by helping to keep your bowel movements regular and reduce stress. If your symptoms are noticeably triggered by stress, try stress management or relaxation techniques.

Keeping a diary to log your symptoms is a great idea. You may even want to jot down any life events that may be occurring at the time to see if there is a connection. If you recognise that certain events trigger your symptoms, it may be easier to deal with the problem that’s causing the symptoms. If these self-help treatments don't work, see your GP for advice. They can help you identify factors that may be making your IBS worse, and suggest other treatments.

Medicines

There are several over-the-counter medicines available from your pharmacist that can relieve some of the symptoms of IBS, including:

anti-diarrhoea medicines. You should only take these as needed, not on a regular basis
laxatives. Some bulk-forming and bowel-stimulating laxatives may help if you have constipation. Bulk-forming laxatives include psyllium-containing products. Bowel-stimulating laxatives such as senna tend to be stronger. However, speak to your GP before using them routinely
antispasmodic medicines. These may help with stomach cramps and wind, and include prescription and over-the-counter medicines
peppermint oil. Peppermint oil capsules, which are available in pharmacies, work as a natural antispasmodic that can relax the smooth muscles in the intestines, providing short-term relief for IBS
probiotics. These contain helpful bacteria and yeasts, and are contained in some yoghurts and other fermented foods as well as in supplement form. There is some scientific evidence that certain strains can be helpful for IBS symptoms, but the evidence isn't conclusive
painkillers. If you need to use painkillers, try to use paracetamol as anti-inflammatory medicines such as ibuprofen or aspirin may make your symptoms worse.

Always read the accompanying consumer medicines information leaflet, and if you have any questions, ask your pharmacist for advice.

Your GP can also prescribe medicines for IBS. These can include prescription-only versions of the medicines mentioned above. Low-dose antidepressants can also be prescribed to help calm symptoms by acting on nerve cells in the gut.

Psychological therapies

The gut and the mind are like two peas in a pod—they’re strongly linked. So, there are many psychological therapies (such a cognitive behavioural therapy, mindfulness meditation, hypnotherapy or psychotherapy) that have been shown to improve or resolve IBS symptoms. If stress seems to be an IBS trigger for you, your GP may consider these types of therapies.