Eat For You Dietitian

What is IBS?

Irritable Bowel Syndrome (IBS) is a common functional gastrointestinal or gut disorder characterised by changes in bowel habits (e.g diarrhoea, constipation or both) and symptoms such as abdominal pain and bloating which are significant to impact day to day life. The term ‘functional disorder’ is a term used for, in this case a disorder on how the gastrointestinal (GI) tract is functioning, without pathological abnormalities, as common medical investigations will often show normal results. IBS is a multifactorial functional disorder which includes the brain-gut axis communication and it is now considered a disorder of the gut-brain interaction (1,2).

How is IBS diagnosed?

The Rome Foundation specifies the Rome IV criteria for diagnosing and treating Disorders of Gut-Brain Interaction (DGBIs). According to IV criteria, the diagnostic criteria for IBS includes recurrent abdominal pain for at least 1 day a week for the past 3 months (symptoms to have started at least 6 months prior), associated with 2 or more of the below:

1. Associated with bowel motion 
2. Associated with change in frequency of bowel motions 
3. Associated with a change in form or appearance of bowel motion (look down the loo to get to know your ‘normal’) 

(3) 

In the UK we also have National Institute for Health and Care Excellence (NICE) guidelines that outlines the diagnostic tests that should be performed by your GP including blood tests and stool (or faecal) tests which check for inflammatory markers, antibodies related to coeliac disease, malabsorption and reviewing your risk of colorectal cancer (4). 

IBS is categorised by subtypes according to symptoms experienced and using the Bristol Stool Chart which categorises our stools from Type 1 (hard pebble-like) to Type 7 (watery diarrhoea) (4). 

1. IBS- Constipation predominant (IBS-C) majority type 1 or 2 less than 3 times a week 
2. IBS- Diarrhoea predominant (IBS-D) – majority type 6 and 7 at least 3 times a day 
3. IBS- Mixed bowel habits (IBS-M) combination of constipation and diarrhoea stools  
4. IBS- Unclassified (IBS-U) – bowel motions are neither constipation, diarrhoea or mixed sub-types, however they meet other diagnostic criteria. 

The Bristol Stool Chart 

(3) 

When do you seek help? 

When presenting the above symptoms are impacting on your quality of life and you being able to do your everyday activities is usually the time. There are key red flags that if present you should seek advice and investigations from your doctor. These include unintentional weight loss, rectal bleeding (particularly if over 50 years old), family history of bowel or ovarian cancer, unknown cause of micronutrient deficiencies, over 60 years old with change in bowel habits of type 6 or 7 (5). 

Is IBS the same as IBD?

IBS is separate from Inflammatory Bowel Disease (IBD) which can be diagnosed as Crohn’s Disease and Ulcerative Colitis (UC), however the symptoms individuals experience can be similar. IBD is a diagnosed disease which causes chronic inflammation to your GI tract. IBD can be seen in investigative imaging. You should undergo the correct diagnostic tests for IBD as the treatment and management options are different to IBS, therefore it is important to seek medical advice. 

Treatment for IBS

Once diagnostic tests have been performed to outrule an organic cause for your presenting symptoms, such as IBD you may then be formally diagnosed with IBS by your Doctor. According to NICE guidelines the first line treatment begins with dietary and lifestyle advice and symptom-targeted medication. 

Our diet is one of the key modifiable factors that shape our gut microbiota, which plays a crucial role in intestinal homeostasis.First line dietary treatment is focused on general advice such as regular meals during the day and avoiding skipping meals or eating too late at night, and reviewing intake of; alcohol, caffeine, high fat/fried foods, dietary fibre diversity and fluids (6). 

The key areas focused on will depend on the subtype of IBS and the primary symptoms of the individual. An important factor to remember is that inclusion is vital to support our gut health and first line treatment is focusing on what we can include in our diet to increase diversity. British Dietetic Association summarises first line treatment including non-dietary approaches such as regular movement,mindfulness and stress-relief advice. This includes gut directed hypnotherapy, and yoga that can often be as effective as dietary modification found in clinical trials (7). The yoga intervention includes different postures and breathing techniques aimed to relax both body and mind, targeting the gut-brain axis (8). 

Should I follow a low FODMAP diet (fermentable oligosaccharides, disaccharides, monosaccharides and polyols)? otherwise known as prebiotic foods

Following implementing first line treatment and there has been minimal improvements in overall functional gut symptoms, under the guidance of Registered Dietitian second line dietary treatment can be followed which does involve an elimination diet, known as the low FODMAP diet. 

As mentioned above, this is not first line dietary treatment for IBS and it should not be followed without guidance from an experienced Registered Dietitian. A key factor of the low FODMAP dietary approach is that it includes 3 phases which should all be followed: elimination phase, reintroduction phase and the personalisation phase. Often in my clinical practice I am speaking to individuals diagnosed with IBS who have been following the elimination phase of the low FODMAP diet and are at a stand-still as they continue to experience their IBS-related symptoms and they are restricted to what they are able to eat.

My main goal when working with an individual with diagnosed IBS or another functional gastrointestinal disorder is that we find a balance where you can enjoy a least restrictive diet as possible. I don’t believe you should be left to fear what you can or cannot eat.

The above is a draft version of an article I wrote for TCN Learning Hub alongside Talia Cecchele. You can read read the first final article here alongside other useful resources and articles.

References 

1. Chong, P.P., Chin, V.K., Loo,i C.Y., Wong, W.F., Madhavan, P. and Yong, V.C., 2019. The microbiome and irritable bowel syndrome–a review on the pathophysiology, current research and future therapy. Frontiers in microbiology, [online] 10 (1136), Available at: https://doi.org/10.3389/fmicb.2019.01136 [Accessed 10 September 2022]. 

2. Bercik, P, 2020..The brain-gut-microbiome axis and irritable bowel syndrome. Gastroenterology & Hepatology, [online] 16(6):322. Available at: https://www.gastroenterologyandhepatology.net/archives/june-2020/the-brain-gut-microbiome-axis-and-irritable-bowel-syndrome/ [Accessed 10 September 2022]. 

3. Rome Foundation. 2016. Rome IV Criteria – Rome Foundation. [online] Available at: <https://theromefoundation.org/rome-iv/rome-iv-criteria/&gt; [Accessed 20 September 2022].

4. National Institute for Health and Care Excellence (NICE), 2008. Clinical guideline [CG61] Irritable bowel syndrome in adults: diagnosis and management. National Institute for Health and Care Excellence. Available at: Irritable bowel syndrome (nice.org.uk) [Accessed 10 September 2022].

5. Knott, L., 2021. Irritable Bowel Syndrome. Patient. Available at: http://www.patient.info/doctor/irritable -bowel-syndrome-pro [Accessed 4 October 2022]. 

6. British Dietetic Association (BDA) UK Website. 2022. Irritable Bowel Syndrome Food Fact Sheet. [online] Available at: <https://www.bda.uk.com/resource/irritable-bowel-syndrome-diet.html&gt; [Accessed 20 September 2022].

7. McKenzie, Y.A., Bowyer, R.K., Leach, H., Gulia, P., Horobin, J., O’Sullivan, N.A., Pettitt, C., Reeves, L.B., Seamark, L., Williams, M. and Thompson, J., 2016. British Dietetic Association systematic review and evidence‐based practice guidelines for the dietary management of irritable bowel syndrome in adults (2016 update). Journal of Human Nutrition and Dietetics. [online] 29(5):549-75. Available at: https://doi.org/10.1111/jhn.12385 [Accessed 10 September 2022]. 

Schumann, D., Langhorst, J., Dobos, G. and Cramer, H., 2017. Randomised clinical trial: yoga vs a low-FODMAP diet in patients with irritable bowel syndrome.