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IBS Symptoms and Food To Avoid

Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common condition that affects your digestive system. According to the NHS, up to one in five people are thought to be affected at some point in their lives (i), though more may be affected because it is thought many people with IBS do not seek medical advice for their symptoms (ii). However, according to the IBS Network charity, around a third of the population are affected at some stage, with 10 to 20 percent of people living in western countries fulfilling the diagnostic criteria for the condition at any one time. IBS is more common in women than in men (around twice as many women are affected as men), and you’re also more likely to develop it when you’re young than when you’re old, usually around the age of between 20 and 30 (ii).

The problem with IBS is that it affects people differently. Some have more severe symptoms than others, while symptoms can flare up from time to time, lasting from a few days to a few months, before improving or disappearing again. There is also usually no obvious physiological cause, which is why IBS can often be referred to as a functional disorder of the bowel or gut (meaning there’s a problem with the function of the bowel/gut but no abnormality in the structure).

What are the symptoms?

People who have IBS may suffer from one or more of the following symptoms, often after eating or drinking:

  • Abdominal pain and cramping/spasms

  • Abdominal bloating and swelling

  • Excessive wind

  • Diarrhoea and/or constipation (doctors may categorise IBS sufferers as having mainly bloating and constipation-based symptoms, mainly diarrhoea symptoms or those who have both)

  • Needing to go to the toilet urgently, especially during the morning

  • Feelings of not having emptied your bowels after going to the toilet

Some people may also have additional symptoms, such as nausea, headache, indigestion, heartburn, tiredness, backache, belching, muscle pains, frequent urination, anxiety and depression.

What causes IBS?

Experts aren’t sure what causes IBS. Several theories have been put forward, but none has been proven to be a direct cause. It is, however, believed by some experts that the following problems are the most likely to cause IBS symptoms:

  • Normally, food travels through your digestive system via rhythmic contractions of the muscles lining your gut, which includes your oesophagus, stomach and intestines. But when the nerves or muscles of the gut become overactive, depending on where the over-activity occurs, it may cause digestive problems such as constipation and diarrhoea. Experts aren’t sure why this over-activity happens, but one theory is that the signals between the gut and the brain become disrupted.

  • Some people may also have an oversensitivity to their digestive nerve signals, which may make symptoms that others hardly even notice become much more severe. Other experts believe some IBS sufferers have a lower threshold for experiencing digestive pain compared with those who aren’t affected.

  • Food intolerances may have a role in triggering IBS symptoms in people who find their symptoms are more severe when they eat certain things.

  • It has been noted that some people develop IBS symptoms after having a stomach bug called gastroenteritis, which causes diarrhoea and vomiting (iii). This has led some experts to believe that IBS may be triggered by a virus.  An overgrowth of bacteria in the intestines may also play a part in the development of IBS symptoms. Discover more about stomach bugs and their effect on the stomach in our guide.

  • Hormones may be implicated in the development of IBS, since women are far more likely than men to develop it. Some women also claim their symptoms are worse around the time of their periods.

  • Stress may also aggravate IBS symptoms, though it’s not thought to be a direct cause. Other psychological factors such as anxiety and depression may also play a part.

Diet and IBS

Even foods that are part of a normal healthy diet can trigger IBS symptoms in some people. A wide range of foods has been implicated in IBS, including fatty or fried foods, caffeine, chocolate, alcohol, fruit, cabbage, broccoli, cauliflower, onions, beans, dairy products, wheat, rye, barley fizzy drinks and even milk.

According to the British Dietetic Association, the best approach is to make changes to your diet according to your IBS symptoms (iv):


Drink about eight glasses of fluids – or two litres – every day and eat more foods that contain fibre, such as whole grains, fruit and vegetables. However, don’t suddenly eat lots of fibre if you’re not used to it; increase your intake gradually. Avoid eating extra wheat bran.


Drink about eight glasses of fluid every day, but don’t have more than a small glass of fruit juice a day, and cut down on caffeine (limit tea, coffee and caffeinated soft drinks to three a day). Also cut back on whole-wheat cereals and breads, replacing them with white bread and cereals. Avoid sorbitol, an artificial sweetener found in sugar-free sweets and food products. Try lactose-free dairy products for a couple of weeks to see if your symptoms improve, as diarrhoea can also be caused by lactose.


Cut down on foods such as beans, pulses, cabbage, cauliflower, broccoli and Brussels sprouts. Only have a small glass of fruit juice per serving, and try lactose-free dairy products for a couple of weeks to see if your symptoms improve, as bloating and wind can also be caused by lactose.

Similar symptoms are also present in those who experience coeliac disease — which can often be misdiagnosed as IBS.

Other general dietary advice includes to eat regular meals and avoid skipping meals or eating late at night. You could also try having more smaller meals throughout the day instead of three big main meals to see if your symptoms improve, and eat slowly, chewing every mouthful. Meanwhile cut back on alcohol (aim for no more than two units a day) and rich or fatty foods. And wherever possible, cook meals from scratch using fresh ingredients rather than relying on ready meals and other processed foods. Keeping a food diary may also help you pinpoint which foods trigger your symptoms. However, if you feel your symptoms are caused by a food intolerance, ask your GP to refer you to a dietician, who can help you confirm which food or foods are the culprits. Some dieticians may also suggest you try a low FODMAP diet, which eliminates complex sugars and has been shown to be an effective dietary therapy for IBS.

Learn more about the low FODMAP diet by visiting King’s College London’s website.

Stress and IBS

The connection between the brain and the gut is well established, and many people affected by IBS say their symptoms become worse when they are experiencing stress and anxiety. Even people who don’t have IBS have experienced ‘butterflies’ in their stomach or feeling sick and needing to find a toilet urgently when they are nervous, anxious or stressed out. If you have IBS, however, you may find yourself trapped in a vicious circle: your symptoms cause stress, anxiety and even depression; meanwhile stress, anxiety and depression make your symptoms worse too.

According to experts, as many as three in five people affected by IBS also experience psychological symptoms such as anxiety or depression, with some believing that stress and anxiety trigger the release of chemicals that may affect your digestive system. It’s also thought that many people with IBS have experienced some sort of emotional trauma or stressful event, typically during childhood (v). This may have played a part in the development of their symptoms or possibly made them more sensitive to stress and the discomfort of abdominal spasms.

If you believe psychological factors play a part in triggering your symptoms, managing your response to stress could help provide relief.

Remedies for IBS

There are several pharmacy medicines designed to relieve some of the symptoms of IBS:

  • Constipation
    Laxatives taken for short periods may help to relieve constipation. There are three main types: bulk-forming laxatives, osmotic laxatives and stimulant laxatives (however, lactulose, a type of osmotic laxative, should be avoided if you have IBS). Find out more about the different types of laxatives by reading Constipation causes.

  • Diarrhoea
    Tablets and capsules containing loperamide are the most popular medicines – called anti-motility medicines – for treating diarrhoea associated with IBS. These work by slowing the contractions of your bowel muscles, which slows down the speed of food passing through your digestive system.

  • Abdominal pain/cramps
    Antispasmodic medicines such as mebeverine and hyoscine butylbromide may help the muscles in your digestive system to relax. If these don’t control your symptoms, you could ask your GP for a tricyclic antidepressant such as amitriptyline, which has other actions besides relieving depression. Tricyclic antidepressants are only available on prescription, and are usually recommended to those with frequent and severe IBS symptoms.

Natural Remedies

Natural remedies may also be helpful for managing the symptoms of IBS, including the following:

Peppermint oil

A traditional herbal remedy, peppermint oil has an antispasmodic action and may help to reduce the production of gas in the gut as well as relieve pain and soothe the gut wall. It is widely used to treat IBS-related symptoms such as abdominal spasms. Numerous studies suggest it is a promising treatment (vi), with one trial showing significant improvements in abdominal pain, bloating, stool frequency and flatulence in those taking peppermint oil tablets compared with those taking a placebo (vii).

Live bacteria

Because they are thought to promote a healthy intestinal bacterial environment, products containing live (or ‘friendly’) bacteria such as acidophilus have been shown to improve constipation in adults and children (viii). They have also had some success in trials for treating diarrhoea associated with IBS (ix).

Soluble fibre

These help to feed the ‘friendly’ bacteria, which is also thought to improve the intestinal environment. Examples of soluble fibre include fructo-oligosaccharides (FOS), which has been used as a treatment for IBS. There is some evidence that FOS may relieve IBS symptoms, including one study that combined FOS with live bacteria (x).

According to the British Acupuncture Council, acupuncture may also help alleviate pain, anxiety and depression, as well as regulate the motility of the digestive tract and raise the threshold of bowel pain.

Meanwhile, relaxation therapy may be worth a try if you find stress or other psychological factors trigger your IBS symptoms (xi). There is also evidence that hypnotherapy may improve IBS symptoms in both adults (xi) and children (xii).

Managing IBS on a daily basis can be difficult at times, but these steps should help to make it a little easier. For more information on a range of other common health conditions, feel free to visit our health library.


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  6. , Peppermint oil (Mintoil) in the treatment of irritable bowel syndrome: a prospective double blind placebo-controlled randomized trial. Dig Liver Dis. ;39(6):530-6.Available online:

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  8. , Effectiveness of probiotics in irritable bowel syndrome: Updated systematic review with meta-analysis.. World J Gastroenterol.. ;21(10):3072-3084.Available online:

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  10. , , , et al. Prescript-Assist probiotic-prebiotic treatment for irritable bowel syndrome: a methodologically oriented, 2-week, randomized, placebo-controlled, double-blind clinical study. Clin Ther. ;27:755-761.

  11. , , et al. Effect of antidepressants and psychological therapies, including hypnotherapy, in irritable bowel syndrome: Systematic review and meta-analysis. Am J Gastroenterol.

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Disclaimer: The information presented by Nature's Best is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.

Our Author - Christine Morgan


Christine Morgan has been a freelance health and wellbeing journalist for almost 20 years, having written for numerous publications including the Daily Mirror, S Magazine, Top Sante, Healthy, Woman & Home, Zest, Allergy, Healthy Times and Pregnancy & Birth; she has also edited several titles such as Women’ Health, Shine’s Real Health & Beauty and All About Health.

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