In 2008 The National Institute for Health & Clinical Excellence (NICE) produced guidelines on the diagnosis and management of irritable bowel syndrome. On looking at all the medical research they decided that:

"A diagnosis of IBS should be considered only if the person has abdominal pain or discomfort that is either relieved by defecation or associated with altered bowel frequency or stool form. This should be accompanied by at least two of the following four symptoms:

  1. 1.Altered stool passage (straining, urgency, incomplete evacuation)

  2. 2.Abdominal bloating, distension, tension or hardness

  3. 3.Symptoms made worse by eating

  4. 4.Passage of mucus

Other features such as lethargy, nausea, backache and bladder symptoms are common in people with IBS and may be used to support the diagnosis"

The guidelines also go on to suggest that people who fit this criteria should also be tested for Coeliac Disease which is an allergy to gluten in wheat, barley and rye. This is not the case for all IBS patients but should be ruled out by your GP.

Helpful websites are:

http://www.nice.org.uk/nicemedia/pdf/CG61IBSQRG.pdf for NICE guidelines

http://www.theibsnetwork.org/  The IBS Network is a UK charity and gives access to an excellent patient self-care plan as well as other useful information on this disabling condition.

Low FODMAP Diet: Fermentable Carbohydrates

Fermentable, Oligo-, Di-, Mono-saccharides and PolyolS (FODMAPs) are short chain carbohydrates (e.g. fructans, galacto-oligosaccharides, polyols, fructose and lactose) that are poorly absorbed in the small intestine. Ingestion of FODMAPs leads to alterations in fluid content and bacterial fermentation in the colon triggering functional gut symptoms in susceptible individuals. Removing FODMAPs from the diet is effective in improving symptoms of people with functional gut disorders like IBS.

In order to prevent nutritional deficiencies, this diet requires input from a specially trained dietitian.


Website for Kings College London where the research in this new diet is being conducted


1. Gibson PR, Shepherd SJ.  Evidence-based dietary management of functional gastrointestinal symptoms: the FODMAP approach. Journal of Gastroenterology and Heptology 2010; 25:252-258

2. Gearry RB, Irving PM, Nathan DM, Barrett JS, Shepherd SJ, Gibson PR. The effect of reduction of poorly absorbed, highly fermentable short-chain carbohydrates (FODMAPs) on the symptoms of patients with inflammatory bowel disease (IBD). Journal of Crohn' and Colitis 2008; 3:8-14.

3. Shepherd SJ, Parker FC, Muir JG, Gibson PR. Dietary triggers of abdominal symptoms in patients with irritable bowel syndrome: randomized placebo-controlled evidence. Clinical Gastroenterology and Hepatology 2008; 6: 765-771.

4. Shepherd SJ, Gibson PR. Fructose malabsorption and symptoms of irritable bowel syndrome: guidelines for effective dietary management. Journal of the American Dietetic Association 2006;106:1631-9.

5. Staudacher HM, Lomer MCE, Whelan K, Irving PI. Implementation of the low FODMAP diet in the UK: How easy is it and does it work? Gut 2010;59:A149.

Food & IBS and other dietary aspects...

IBS is rarely caused by a food allergy, but is often caused by an intolerance to certain foods in the diet. These foods can result in excess gas and wind which stretches the muscles in the abdomen causing pain, discomfort, bloating and can also result in diarrhoea. The symptoms can occur several hours after eating the offending food which can make pin pointing the exact cause very difficult. Often the offending food items are eaten regularly and in normal portions.

However, before you tackle any specific foods it is vital that you establish a healthy eating pattern, as often this is all that is needed to rid you of the IBS symptoms:

  1. 1.Make sure you eat 3 regular meals per day - never skip meals - have breakfast, lunch and dinner

  1. 2.Sit down and take your time to eat - never eat in a rush

  1. 3.Take regular exercise - walking, swimming, cycling, football, tennis, pilates, yoga etc

  1. 4.Make time to relax

If you feel that any of these are impossible then specific dietary intervention beyond this is unlikely to help.

Once you have the basis of a healthy eating pattern and you are still suffering from symptoms of IBS then there are several areas to look at including:


It is vital that you don't just cut out large groups of food from your diet without help and advice as this can lead to nutritional deficiencies and further complicate your symptoms with the introduction of other illnesses.  Keeping a detailed food/drink & symptom record for 7 days may help you pin point specific problem foods, but it is always sensible to seek the advice of a qualified dietitian.  Your GP can refer you to your local NHS dietetic service.

Lactose Intolerance - This is NOT an 'allergy' as lactose intolerance does not involve the immune system. In fact it is a physical inability to process the sugar found in animal milks (cow, sheep, goats). Most people with lactose intolerance relating to IBS can tolerate small amounts in the diet but if they consume too much then they can suffer from bloating, diarrhoea, abdominal pain and wind.

Dairy Allergy - This is when the immune system reacts to the protein found in products containing animal milk. Often if the person is allergic to cows milk then they will also be allergic to the similar proteins found in goats and sheep and any other mammalian milk. Symptoms can be similar to lactose intolerance and can result in bloating, abdominal pain, reflux, wind, diarrhoea or even constipation. An 'allergy' may need the person to remove even small traces of dairy from their diet and this requires guidance and support from a dietitian.

Fibre - when constipation is an issue then soluble fibre can be very helpful although it can also cause the bowel to contract so increasing pain, bloating, flatulance and diarrhoea. So if you do increase the soluble fibre then do so gradually with no more that 1 extra portion over a 2 day period. Increase you intake of oats, fruit, vegetables and golden linseeds.

Oats and Golden Linseeds - These are thought to help reduce constipation and interestingly they may also help with symptoms of bloating and wind.

Resistant Starches - these are starches which the body can not digest properly and they should be reduced in an IBS diet. They are found mainly in processed/manufactured/reheatable foods containing starch eg. oven chips, fried rice, crisps, reheated breads, garlic bread, pizza base, potato waffles, pre-made potato or pasta salad, shop bought cakes and biscuits. Use freshly cooked, homemade versions of these foods instead. Resistant starches are also found in green bananas, pulses, sweetcorn and bran.

Probiotics - Live yoghurts, supplements, fermented drinks and probiotics will need to be taken for at least 1 month at the dose recommended by the manufacturer. Monitor the effect on your symptoms. If a brand does not seem effective then perhaps consider an alternative brand and the types of bacteria vary between products.

Prebiotics - these are preparations that contain the food to feed the good bacteria in your gut so encouraging more good bacteria to grow. They are not damaged during digestion as can be the case with probiotics but they can cause an increase in wind and bloating in certain individuals.  They are often labelled as FOS, inulin or oligofructose.

Caffeine & Alcohol - Limit your caffeine intake to 3 cups per day eg. coffee, tea, cola and try not to have alcohol every day and no more than 2 units a day. It is also useful to note that coffee increases spasms in the bowels whether or not it contains caffeine and hence decaffeinated beverages may be of little use.

High Fat Foods - diarrhoea may be caused by a high intake of fatty foods eg. chips, fast food, burgers, sausages, crisps and cake. Try the low fat versions.


"The FODMAP diet has now become a well recognised and evidence-based nutritional approach to IBS.  Guys & St Thomas' Hospital in London has over 70% success rate with their IBS patients - as long as they are seen by a FODMAP trained dietitian.”  Marianne Williams