Irritable Bowel Syndrome and diet
Irritable Bowel Syndrome (IBS) is a medical term used to describe a collection of gut symptoms. Dietary changes can often help IBS symptoms and sometimes simple changes are all that are needed.
In this fact sheet:
Symptoms vary from one individual to another and can be worse for some than others. It is a very common condition affecting around one in five adults. An assessment for IBS should be considered if you have had any of the following symptoms for at least six months: abdominal pain or discomfort, bloating, or change in bowel habit.
A diagnosis of IBS should be considered only if there is abdominal pain or discomfort that is either relieved by defaecation or associated with a change in bowel habit. This should be accompanied by at least two of the following four symptoms:
altered stool passage (straining, urgency, incomplete evacuation)
- abdominal bloating (more common in women than men), distension, tension or hardness
- symptoms made worse by eating
- 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. It is important to have a diagnosis of IBS confirmed and other conditions such as coeliac disease and inflammatory bowel disease ruled out. Four reasons to consult your doctor for referral to see a specialist are where you have possible IBS symptoms and any of the following:
- unintentional and unexplained weight loss
- rectal bleeding
- a family history of bowel or ovarian cancer
- a change in bowel habit to looser and/or more frequent stools persisting for more than six weeks in a person aged over 60 years
What steps can I take if I have Irritable Bowel Syndrome?
- eat three regular meals a day
- try not to skip any meals or eat late at night (smaller meal sizes may ease symptoms)
- limit alcohol intake to no more than two units per day and have at least two alcohol free days a week
- reduce intake of caffeine-containing drinks e.g. no more than two mugs (three cups) a day reduce intake of fizzy drinks
- drink at least eight cups of fluid per day, especially water or other non-caffeinated drinks, for example herbal teas
- cut down on rich or fatty foods including chips, fast foods, pies, batter, cheese, pizza, creamy sauces, snacks such as crisps, chocolate, cake and biscuits, spreads and cooking oils, and fatty meats such as burgers and sausages
- reduce your intake of manufactured foods and cook from fresh ingredients where possible
- limit fresh fruit to three portions per day (one portion is 80g)
Seek advice from a healthcare professional about the amount of dietary fibre that is right for you.
take time to relax – relaxation tapes, yoga, aromatherapy or massage may help
- take regular exercise such as walking, cycling, swimming
- take time to eat meals – chew your food well
- keep a food and symptom diary whilst you are making changes so you can see what has helped
- make one change at a time so that you can see what has helped
- make changes according to your symptoms
If symptoms include bloating and wind:
- limit intake of gas producing foods e.g. beans and pulses, Brussels sprouts, cauliflower, and also sugar-free mints/chewing gum
- you may find it helpful to eat oats (such as oat-based breakfast cereal or porridge) and linseeds (up to one tablespoon per day)
If symptoms include constipation:
- try to gradually increase your fibre intake – any sudden increase may make symptoms worse. Rich sources include wholegrains, oats, vegetables, fruit and linseeds. They help to soften stools and make it easier to pass
- try adding one tablespoon per day of brown or golden linseeds (whole or ground) to breakfast cereal, yoghurt, soup or on salad. Have around a small glass/teacup (150ml) of fluid with each tablespoon of linseeds taken
- avoid eating extra wheat bran
If symptoms include diarrhoea:
Replace lost fluids by drinking plenty.
- limit caffeine intake from tea, coffee and soft drinks to three drinks per day
- try reducing intake of high‑fibre food (such as whole-wheat breakfast cereals and breads)
- avoid sugar-free sweets, mints, gum and drinks containing sorbitol, mannitol and xylitol
You may wish to try ‘probiotic’ supplements, yoghurts or fermented milk drinks. Take them daily for at least four weeks to see if they improve symptoms. If they do not appear to help then you could try an alternative brand. Read our Probiotics Food Fact Sheet.
Give your bowels time to adjust to any changes. If your symptoms persist after following general lifestyle and dietary advice, try to re-introduce the foods you have cut out and ask your doctor to refer you to a healthcare professional with expertise in dietary management, who can ensure your diet is nutritionally adequate whilst following dietary intervention e.g. a dietitian.
They may suggest you trial a diet restricted in shortchain fermentable carbohydrates (also known as a low FODMAP diet).
Most people will be able to see an NHS dietitian after being referred by a doctor, health visitor or other medical staff. You may be able to selfrefer. Alternatively, if you wish to see a private dietitian, you can search online at freelancedietitians.org, which is run by the BDA’s Freelance Dietitian Group.
NOTE: IBS is not caused by food allergy. If you feel that you may be suffering with a food allergy, please refer to Allergy UK (www.allergyuk.org) or Anaphylaxis Campaign (www.anaphylaxis.org.uk) for further information.
Dietary changes can often help IBS symptoms and sometimes simple changes are all that are needed. Remember to monitor your progress by keeping a food and symptom diary. If you need further help, ask your doctor to refer you to a healthcare professional with expertise in dietary management.
Download this information as a PDF.
This Food Factsheet is a public service of The British Dietetic Association (BDA) intended for information only. It is not a substitute for proper medical diagnosis or dietary advice given by a dietitian.
If you need to see a dietitian, visit your GP for a referral or a private dietitian.
Written by Yvonne McKenzie, Liane Reeves, Marianne Williams, Dietitians on behalf of the BDA Gastroenterology Specialist Group and the BDA Food Allergy Specialist Group.
© BDA January 2019. Review date: January 2022.