What is IBS and how is it diagnosed?

What is IBS and how is it diagnosed?

Caroline Tuck - Research Dietitian & PhD Candidate, 05 November 2015

Irritable Bowel Syndrome (IBS) is a condition of the gastrointestinal tract. IBS causes symptoms such as abdominal pain, bloating, wind, constipation and diarrhoea. However, these symptoms can be caused by other more sinister conditions, so it is important to get the correct diagnosis. IBS cannot be diagnosed via a test e.g. blood test, scan or bowel biopsy (tissue sample which is sent to a laboratory for analysis). Instead, it is diagnosed based on symptom criteria after the exclusion of all other gastrointestinal disorders.

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How do you know if you have it?

Firstly, we recommend you speak with your GP. Your GP may recommend some investigations or that you see a Gastroenterologist. This is to ensure that other gastrointestinal disorders are ruled out, for instance coeliac disease and inflammatory bowel disease (i.e. Crohn’s disease or ulcerative colitis). These diseases cause inflammation of the gut wall and left untreated, can lead to other serious problems including nutritional deficiencies and some cancers, so it is important they are excluded. If you have had other conditions ruled out, a diagnosis of IBS might be made.

Your doctor should use “Rome III” criteria to diagnose your IBS. These criteria provide specific guidelines on the type and frequency of symptoms that should be present for a diagnosis of IBS to be made. Your doctor will compare your symptoms to the criteria to determine if you have IBS.

What is IBS and what causes it?

What is IBS and how is it diagnosed?_58460dae

The cause of IBS is not known. While many factors are likely to contribute to disease onset, one specific cause has not been identified and it is likely that multiple factors are involved. Factors thought to cause IBS include visceral hypersensitivity (i.e. a more sensitive gut); changes in the way the gut moves food through the gut; changes in gut bacteria populations, and disturbances in the way the brain processes information from the gut. We also know that lifestyle factors, such as diet, stress and exercise can affect IBS symptoms.

There are many IBS treatments available, including the low FODMAP diet, which was developed by our team at Monash University. The low FODMAP diet has been shown to improve symptoms in around 70% of patients, but it is not the only therapy for IBS. Because each person may respond to therapies differently, it is important to talk to your doctor about the treatment options available.

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What do I do if I suspect I have IBS?

First things first – see your GP! It is especially important not to make any changes to your diet before undergoing any tests, because changing your diet may interfere with the results. If you or your GP think diet may have affect your condition, then see your local Dietitian who has experience in this area (see also our related blog post: https://www.monashfodmap.com/blog/top-5-reasons-why-you-should-see_22/).

To find a gut-specialist dietitian in Australia, visit www.daa.asn.au - Find an Accredited Practising Dietitian page and select "Gastrointestinal (Bowel) disorders" in the area of practice dropdown box.

For all other countries, visit the webpage and search under "gastrointestinal" or "digestive disorders"

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