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What is IBS

IBS is a very common gastrointestinal disorder that affects 1 in 7 people. Once known as ‘spastic colon’, abdominal pain and abnormal bowel habits (constipation, diarrhea or a mixture of both) are key features of IBS.(1) Other symptoms may also be present including:

  • bloating (the sensation of an inflated balloon in the abdomen)
  • distension ( a visible increase in abdominal girth)
  • excessive gas (farts / wind)
  • urgency to defecate (poo)

What causes IBS?

We still do not know what causes IBS, although a number of factors are thought to play a role. These includes:

Gut sensitivity

People with IBS may have a more sensitive gut - this is sometimes called ‘visceral sensitivity’

Altered gut motility

The contents of the gut may move unusually quickly or slowly - this is sometimes called ‘altered gut motility’.

Bacterial

People with IBS may have an imbalance of ‘good’ and ‘bad’ bacteria in their gut - this is sometimes called ‘dysbiosis’.

Leaky gut

People with IBS may have a slightly inflamed or ‘leaky’ gut that is not readily detected on usual testing.

Infections

Sometimes IBS starts after a severe gut infection such as gastroenteritis - often termed 'gastro'.

Gut sensitivity - people with IBS have an overally sensitive gut wall

Altered gut motility - people with IBS have disturbances in the speed at which contents move through the gut

Bacterial - people with IBS may have alterations in their gut microbiota

Other possible causes of IBS - infections, 'leaky gut', etc.

Symptoms of IBS 

It is common for the symptoms of IBS to fluctuate over time - there are good times and bad times. IBS symptoms can vary greatly between individuals and they might vary over time. These include:

Abdominal Pain

Abdominal pain or discomfort might occur anywhere in the abdomen, though most commonly it is experienced in the mid or lower abdomen.

Bowel changes

This can be constipation, diarrhea or alternating between constipation and diarrhea - meaning erratic and unpredictable bowel habits.

Bloating & Distension

Abdominal bloating where the abdomen feels full and distended, and abdominal distension where the abdomen is seen to be distended.

Flatulence

Excessive flatulence where passage of flatus/gas/wind is greater than usual.

Fatigue

Fatigue may also occur because of abdominal symptoms.

Abdominal pain

Constipation

Diarrhea

Bloating and distension

Will I have IBS forever?

IBS is considered a chronic condition, which means it is usually present over the long-term. However, IBS symptoms often come and go over time. Symptoms may improve or disappear for a time, and then return, or new symptoms may develop. Symptoms may also change from being quite mild, to sometimes being quite severe. Some people also find that their usual bowel habit (e.g. diarrhea or constipation) changes. For example, they may suffer mostly constipation or mostly diarrhea for a while, and then develop more of a mixed bowel habit, (sometimes experiencing diarrhea and sometimes experiencing constipation).(1)

Getting a diagnosis of IBS

IBS should not be ‘self-diagnosed’. Instead, if you suspect you have IBS, see your medical doctor for a proper diagnosis. Getting a diagnosis is important to rule out other more serious conditions, such as coeliac disease, inflammatory bowel disease and endometriosis. Your doctor can run tests to rule these conditions out. Once you are diagnosed with IBS, you can choose treatments that are best targeted to your condition.

Symptoms to tell your doctor about

There are certain symptoms that are considered ‘red flags’ or ‘alarm features’ in IBS. This is because they are sometime present in more serious conditions, such as celiac disease or inflammatory bowel disease. If you experience any of the following symptoms, make sure you tell your doctor:

  • Blood in the stool
  • Anemia
  • Weight loss that is unintentional
  • Fever
  • Symptoms that are severe or getting progressively worse
  • Daily diarrhea
  • Bowel motions at night
  • Having a family history of other bowel diseases

Your doctor may want to run additional tests to rule other conditions out if you suffer any of these symptoms.

Tests for IBS

The type and number of tests needed to diagnose IBS can vary quite a lot between individuals. If your doctor identifies no symptoms that he or she is concerned about (such as blood in the stool or anemia), few (if any) tests are needed to confirm a diagnosis of IBS. However, sometimes additional tests are needed to rule out other conditions (such as celiac disease) and to confirm the diagnosis of IBS. Common tests can include:

  • Blood tests
  • Stool tests
  • Gastroscopy/colonoscopy

Unreliable tests for IBS

There are also many tests that are widely available, but not helpful in diagnosing IBS. These include:

  • Breath tests
  • IgG food intolerance tests 
  • Faecal microbiota testing 

We do not recommend the use of these tests.

IBS Treatment

There are a large number of treatments available to manage IBS symptoms. These treatments will not cure IBS, they simply help relieve the symptoms of IBS. Some of these treatments are well supported by scientific evidence, and others are not. Working with your doctor or dietitian will help you to identify a treatment that is best suited to your main symptoms and the underlying cause of these symptoms. You may need to try several different treatments before you find one that suits your lifestyle and improves your symptoms. But remember, when trying different treatments, try only one at a time. This will give you the clearest picture about which treatments are working, and which are not.

You may be advised to begin by trying non-drug therapies. These are generally better at improving a range of symptoms, whereas drug therapies tend to target specific symptoms. An advantage of non-drug therapies is that they can often be used long-term, without ongoing costs, with few risks, and sometimes, with minimal health professional input.

Below is a list of therapies sometimes used to manage symptoms of IBS:

What is the best diet for IBS?

There are many different dietary strategies that can help relieve IBS symptoms. Research at Monash University and numerous other centres around the world has shown that a low FODMAP diet improves IBS symptoms in around 3 out of 4 IBS sufferers. Because of this, a low FODMAP diet is recommended as the first treatment choice for people with IBS.

References:

  1. El-Serag HB, Pilgrim P, Schoenfeld P. Systemic review: Natural history of irritable bowel syndrome. Aliment Pharmacol Ther. 2004;19(8):861-70.
  2. Zhou Q, Verne GN. New insights into visceral hypersensitivity--clinical implications in IBS. Nat Rev Gastroenterol Hepatol. 2011;8(6):349-55.
  3. Sadik R, Stotzer P-o, Simrén M, Abrahamsson H. Gastrointestinal transit abnormalities are frequently detected in patients with unexplained GI symptoms at a tertiary centre. Neurogastroenterology & Motility. 2008;20(3):197-205.
  4. Simrén M, Barbara G, Flint HJ, Spiegel BMR, Spiller RC, Vanner S, et al. Intestinal microbiota in functional bowel disorders: a Rome foundation report. Gut. 2013;62(1):159-76.
  5. Mearin F, Lacy BE, Chang L, Chey WD, Lembo AJ, Simren M, et al. Bowel Disorders. Gastroenterology. 2016.
  6. Hungin AP, Whorwell PJ, Tack J, Mearin F. The prevalence, patterns and impact of irritable bowel syndrome: an international survey of 40,000 subjects. Aliment Pharmacol Ther. 2003;17(5):643-50.
  7. Maxton DG, Morris JA, Whorwell PJ. Ranking of symptoms by patients with the irritable bowel syndrome. BMJ. 1989;299(6708):1138-.
  8. Halmos EP, Power VA, Shepherd SJ, Gibson PR, Muir JG. A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology. 2014;146(1):67-75.e5.
  9. Peters SL, Yao CK, Philpott H, Yelland GW, Muir JG, Gibson PR. Randomised clinical trial: the efficacy of gut-directed hypnotherapy is similar to that of the low FODMAP diet for the treatment of irritable bowel syndrome. Aliment Pharmacol Ther. 2016;44(5):447-59.