Bloating and IBS

How many people are affected by IBS in the UK?

Around a third of people in the UK suffer some of the symptoms associated with IBS and for 1 in 10 people the symptoms are so bad they go to see a doctor.

What are the symptoms?

The main symptoms of IBS can vary from mild to severe and include some of the following:

  • Abdominal pain and spasm
  • Diarrhoea – loose or ribbon-like motions
  • Constipation – solid, rabbit pellet-like motions
  • Alternating diarrhoea and constipation
  • Abdominal bloating
  • Rumbling, flatulence and wind
  • Sense of incomplete emptying of bowels
  • Urgency to open bowels.

And sometimes nausea, tiredness, belching and vomiting.

Note – indigestion or feeling full or bloated in your stomach after eating is not usually IBS. IBS symptoms are usually lower in the abdomen. Other conditions that may be mistaken for IBS include lactose intolerance and coeliac disease amongst others. A gastroenterologist will help find the diagnosis as there are tests available to exclude or confirm both these conditions.

IBS – what causes it?

We do not know what causes IBS, but we do know that symptoms come and go and that stress and diet may have a role to play. IBS sometimes develops after a bout of gastroenteritis, after a course of antibiotics or after surgery but triggers often remain undetected.

What are the most common causes of bloating?

A survey by the Grain Information Service found that 20% of the population claim to suffer from bloating. Many believe that bloating is caused by irritable bowel syndrome or as a result of suffering from wheat intolerance. However the main causes of bloating were linked to hormone fluctuations (32%), over-eating/ irregular meal patterns (28%) and stress related indigestion (27%). Many people feel bloated at lunch or in the evening, especially after a heavy meal. Recent weight gain also adds to discomfort after eating. Irregular meals, skipping meals and drinking a lot (especially fizzy drinks) at meal times can really aggravate that bloated feeling. The answer is to try and spread your food and drinks more evenly over the day. Small regular meals and snacks are the best option. Some people find the bloating is worse after eating too much fruit, spicy food and fizzy carbonated drinks – all of which can cause gas and bloating. Cut down on these foods to stop the bloating. Being constipated can cause bloaing and general discomfort in the abdomen. Constipation is usually linked to a lack of fluid and dietary fibre and can be greatly helped by drinking at least 8 -10 cups or glasses of non-alcoholic drinks a day and eating more fibre containing food including wholemeal bread and high fibre foods like breakfast cereals. Some people find that eating certain foods like banana make them feel ‘bunged up’. This is usually specific to an individual so foods should not be excluded without a firm basis. Being open minded is the key.

How do I find out if I have IBS?

Once your Doctor has ruled out any serious medical condition he may send you to a registered dietitian for help in sorting out what you should or should not eat.

Keeping a food and symptom diary, which lists what you eat, drink and any symptoms can be used to pin point any foods that could be causing you a problem. The dietitian may then suggest you change what you eat for a trial period. This is the basis of an exclusion and reintroduction diet. It may also include:

  • This could be simply drinking more fluid and eating more fibre containing foods to see if treating constipation reduces the IBS type symptoms.
  • Or the timing and size of your meals may be changed.
  • Often a probiotic yoghurt or drink may be suggested, especially if you have been taking antibiotics or had gastroenteritis

If food intolerance is suspected an exclusion diet may be suggested – in 3 stages:

  1. Exclusion stage – when you avoid the suspect food or foods for 2-3 weeks, continuing to keep a food diary.
  2. Re-introduction or ‘testing’ stage – when you add back the avoided foods – one at a time – in gradually increasing amounts one at a time until you reach normal serving sizes usually over 3 days.. If symptoms return, then you should continue to exclude that food from your diet. If no reaction is noted, then add the food back into your diet.
    Please note we do not suggest testing any food thought to have triggered a serious allergic reaction.
  3. Maintenance stage – continue avoiding foods known to cause a reaction, but making sure your diet is nutritionally adequate. The dietitian will recommend the best way to manage the restricted diet to ensure it is nutritious, varied and tasty. She will provide product information and recipes. Avoided foods should be re-tested from time to time, as quite often with IBS, foods that were a problem can be eaten with no symptoms after a few months.

If you are having a bad IBS ‘attack’ it can seem as if all foods cause a problem. This reaction is probably because your bowel is so sensitive at this time and as the symptoms improve so will your ability to eat a wider range of foods.

Any testing should involve gradual reintroduction and diary keeping. Even only being able to tolerate a small amount of a food, can allow a much more varied diet.


  • Following a strict exclusion diet long-term without follow-up
  • Following a strict exclusion diet long term without ‘re-testing’
  • Following a restricted diet that makes you feel unwell
  • Following a restricted diet that causes rapid weight loss.

Who can you trust?

‘Tests’ carried out in health food shops, bought off the internet or carried out by some unqualified health practitioners or nonregistered nutritionists are not reliable and frequently lead to incorrect results. This can lead to people following unnecessarily strict diets. Even more worrying is that such tests and diets can delay the diagnosis and treatment of the true condition. Independent sources such as the British Dietetic Association and the Food Standards Agency advise consumers not to self-diagnose but to go and see their GP who will also refer to a specialist clinic if required. A GP survey found that 90% of GPs agree that women are putting their health at real risk by eliminating foods without any medical consultation and that questionable and potentially harmful advice by unregistered nutritionists and other ‘health guru’s’ is often to blame.

Where to get help?

How do you know who is the best person to talk to? Not all so-called ‘experts’ are actually qualified in nutrition and dietetics. When looking for someone to consult about a suspected food allergy, consult only the following:

  • A General Practitioner (GP)
  • A Registered Dietitian: qualified dietitians work for the NHS or in private practice and are usually accessed through your GP. All practicing dietitians must be Registered – look out for the letters RD after their name and check their registration is up to date with the Health Professions Council:

Supporting research and further information

Please download our factsheet on Bloating and IBS, contact our press office or visit

Useful contacts

British Dietetic Association: (see factsheet under ‘foodfacts’)

The IBS Network:

British Nutrition Foundation:

Flour Advisory Bureau:

CORE (previously Digestive Disorders Foundation):