Irritable bowel syndrome (IBS)
Key facts
- If you have irritable bowel syndrome (IBS), you may have abdominal pain, a bloated stomach and irregular bowel habits.
- You may have chronic diarrhoea or constipation, or switch between diarrhoea and constipation.
- Your doctor will rule out other illnesses before diagnosing IBS.
- Your doctor may suggest treatments for IBS, including several non-medicine treatments.
- A dietitian may help identify your triggers and help you manage your symptoms.
What is irritable bowel syndrome (IBS)?
Irritable bowel syndrome (IBS) is a common condition that affects your digestive system. Symptoms are sometimes linked to:
- certain foods
- lifestyle habits
- stress levels
- your mood
IBS affects around 1 in 5 people. Females are more likely than males to be affected.
In IBS, medical tests such as blood tests, endoscopy and imaging tests don't show anything abnormal.
IBS is a different disease from inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis.
IBS symptoms can have a huge impact on your quality of life.
What are the symptoms of irritable bowel syndrome?
Some key symptoms of IBS are:
- abdominal pain or discomfort
- stomach bloating and wind
- diarrhoea or constipation, or alternating between these 2 symptoms
You may feel your bowel movement was incomplete (even after a poo).
Often your pain can be relieved by passing wind or faeces (poo).
IBS symptoms in females
In females, IBS symptoms can get worse around the time of menstruation (your period).
The levels of hormones, such as oestrogen and progesterone, change during your menstrual cycle. Your gut has receptors for these hormones, so your IBS symptoms can be impacted by these hormone changes.
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What causes irritable bowel syndrome?
While the exact cause of IBS is not clear, some common IBS triggers are:
- diet
- stress
- infection
- medicines
You may find that some foods make your symptoms worse. These 'trigger foods' differ from one person to the next.
Your IBS symptoms might have started after an infection such as gastroenteritis ('gastro').
Taking certain medicines may trigger your symptoms — such as antibiotics, antacids and pain-relief medicines.
See your doctor or pharmacist to check whether these medicines may have triggered your symptoms.
When should I see my doctor?
It's important to see your doctor if you get symptoms. Your doctor will check for other conditions before diagnosing you with IBS.
If you have IBS, you should see your doctor if:
- you are concerned about your symptoms
- your symptoms are severe or ongoing
- you notice blood in your stools (poo)
- you have unexplained weight loss
- you have a fever or severe diarrhoea
It's important that your doctor sees you to rule out a more serious condition.
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How is irritable bowel syndrome diagnosed?
IBS is a diagnosis of exclusion. This means that your doctor can only diagnose IBS after ruling out other conditions that could be causing your symptoms. These could include:
- infections
- inflammatory bowel disease (IBD)
- coeliac disease
- food allergies
- bowel cancer
Your doctor may rule out these conditions by referring you for investigations such as:
- blood tests
- stool tests
- endoscopic investigations such as sigmoidoscopy or colonoscopy
Your doctor may diagnose you with IBS, if:
- you've been experiencing IBS symptoms for at least 6 months
- your test results are normal
How is irritable bowel syndrome treated?
There are a wide range of treatment options available for IBS.
Diet and lifestyle changes are often the best long-term strategy to ease your symptoms. A dietitian can make sure you don't miss out on any key nutrients. They can also help you to identify and exclude foods that trigger your IBS.
Other treatments that may help you are:
- prescription medicines and over-the-counter medicines, including anti-depressants, laxatives and anti-diarrhoeal medicines
- herbal remedies such as peppermint oil
- nutritional supplements such as fibre and probiotics
- physical activity such as yoga
- psychological therapies such as cognitive behavioural therapy (CBT) and hypnosis
Living with IBS
Your IBS symptoms can often improve by adopting healthy lifestyle habits, including dietary changes.
Dietary fibre adds bulk to your stools (poo). This makes your stools soft and easy to pass. Your IBS symptoms may be worse if you don't eat the right amount of fibre.
Sources of dietary fibre are:
- fruits
- vegetables
- high fibre cereal
It's best to slowly increase your dietary fibre intake up to 25-30g per day. This is the recommended daily intake of dietary fibre. This helps avoid bloating and wind-related discomfort.
If this is difficult for you, ask your pharmacist for a soluble fibre supplement, such as psyllium.
Some foods and drinks commonly trigger IBS. Try to reduce your intake of these to see if it helps:
- gas-producing foods, such as onion, cabbage, Brussels sprouts, dried beans, lentils and cauliflower
- foods with lactose (milk sugar), such as milk, ice cream and some yoghurts
- alcoholic drinks
- artificial sweeteners, such as aspartame, sorbitol and mannitol
A dietitian can work with you to find your triggers. They can also create a balanced diet that suits you.
Sometimes, a low FODMAP diet may be recommended for you. FODMAP is short for fermentable oligosaccharides, disaccharides, monosaccharides and polyols. These are the chemical names for different sugars that are poorly absorbed in your gut. For some people, these can trigger symptoms of IBS.
Other strategies that may improve your IBS symptoms are:
- physiotherapy to help address pelvic floor dysfunction
- hypnotherapy
- relaxation exercises
What are the complications of IBS?
IBS is often a mild condition that can be well-managed by diet and other lifestyle changes. However, it may affect your quality of life and can be stressful to manage.
Some people with IBS develop:
If IBS is causing you to feel down, anxious or upset, there are IBS-specific psychological support services. Talk to your doctor about whether they are right for you.
People with IBS have a small risk of faecal incontinence. The Continence Foundation of Australia can help with strategies where this is due to constipation or diarrhoea. Call their toll-free helpline for advice on 1800 33 00 66.
Can IBS be prevented?
You can help prevent IBS symptoms by:
- maintaining a healthy lifestyle
- avoiding foods and other things that trigger your symptoms
Resources and support
Monash University has information on FODMAPs and Irritable Bowel Syndrome.
The Continence Foundation of Australia has a National Continence Helpline — call 1800 33 00 66. They also have a National Public Toilet Map.
Dietitians Australia has information on IBS.
Other languages
The Continence Foundation of Australia has fact sheets on a healthy diet and bowels. These are translated into over 25 different languages.
Learn more here about the development and quality assurance of healthdirect content.
Last reviewed: December 2024
