Irritable bowel syndrome, usually shortened to IBS, is a common disorder affecting the digestive system. It can cause abdominal pain or cramping, bloating, diarrhoea, constipation, or a pattern that alternates between the two. Symptoms often come and go, and their intensity can vary considerably. For some people IBS is an occasional inconvenience; for others it has a marked effect on work, travel, social life and confidence around food.
IBS does not damage the bowel, but that does not make the symptoms insignificant. It is now commonly described as a disorder of gut–brain interaction: the digestive tract and nervous system appear to communicate differently, affecting bowel movement, sensitivity and the way discomfort is experienced. Stress may worsen symptoms, but IBS is not “all in the mind”. Food, hormones, illness, medicines and changes in routine can also influence how a person feels.
Recognising the pattern
The main features of IBS are recurring abdominal pain or discomfort alongside a change in bowel habit. Some people mainly experience constipation, some mainly diarrhoea, and others have a mixed pattern. Bloating, urgency, incomplete emptying, flatulence, nausea and tiredness may also occur.
Recognising serious symptoms
Because these symptoms overlap with other conditions, self-diagnosis is unwise. A GP can assess the pattern and, where appropriate, arrange tests to exclude problems such as coeliac disease or inflammatory bowel disease. Seek medical advice promptly if symptoms include unexplained weight loss, bleeding from the bottom or bloody diarrhoea, a persistent abdominal swelling or lump, marked paleness, palpitations, or shortness of breath. New symptoms that repeatedly wake you at night also deserve medical attention.
Diet and daily habits
There is no single “IBS diet”. A food that causes difficulty for one person may be entirely comfortable for another, so the aim is to identify a manageable pattern without removing foods unnecessarily.
Regular meals are a sensible starting point. Try not to skip meals or leave very long gaps, and take time to eat rather than rushing. Chewing thoroughly and eating in a calmer setting may reduce the amount of swallowed air and make it easier to notice fullness. Adequate fluid is also important; for many adults, around 1.5 litres of water or non-caffeinated drinks a day is a practical guide, although individual needs vary.
A short food-and-symptom diary can reveal useful connections. Record meals, drinks, bowel symptoms, stress, sleep and any medicines or supplements. Look for repeated patterns rather than blaming a food after one uncomfortable day. Common triggers can include large or fatty meals, spicy foods, alcohol, fizzy drinks, excess caffeine and the sweetener sorbitol.
Fibre needs particular care. Constipation may improve with soluble fibre from foods such as oats, pulses, carrots or linseeds, introduced gradually with enough fluid. By contrast, a sudden increase in bran or other coarse fibre can aggravate bloating or pain in some people. Diarrhoea may call for a temporary reduction in very high-fibre foods, but long-term restriction should be discussed with a suitably qualified professional.
What about low-FODMAP diets?
A low-FODMAP diet can help some people whose symptoms persist despite straightforward changes. It temporarily reduces certain fermentable carbohydrates before foods are systematically reintroduced. It is not intended to be a permanent, highly restrictive diet and is best undertaken with a dietitian or another healthcare professional who has specific expertise in this approach. Unsupervised restriction can make the diet nutritionally poorer and may leave a person avoiding far more foods than necessary.
Useful supplements
Supplements should be selected for the individual rather than used automatically. Product directions and advice from an appropriately qualified professional should take precedence over general information.
| Supplement | Effects |
|---|---|
| Broad-spectrum gut bacteria | Helps replenish the intestinal flora with beneficial bacteria, which may be especially helpful where diarrhoea is present. |
| Digestive enzymes | Supports the digestion of food and may help reduce digestive irritation and inflammation. |
| Lactobacillus acidophilus | Helps restore beneficial bacteria within the intestinal flora and may be particularly useful where diarrhoea is present. |
| Krill oil or marine fish oil | Provides anti-inflammatory support. |
| Aloe vera | Offers prebiotic support and may help encourage a favourable bowel environment and healthy functioning. |
| Magnesium citrate | May have an antispasmodic effect. |
| Fructo-oligosaccharides (FOS) | Provides prebiotic support and may help promote a favourable bowel environment and healthy functioning. |
| Herbal antispasmodic complex Such as valerian, hops, hawthorn and passionflower | These herbs are traditionally valued for their soothing properties. |
| Pantothenic acid (vitamin B5) | Supports the proper functioning of the gastrointestinal tract. |
| Peppermint oil capsules | Has a recognised antispasmodic effect on the stomach and intestines. |
| Spirulina | Provides anti-inflammatory support. |
| Plant sterols | Provides anti-inflammatory support. |
| Hop alpha acids | May help to reduce pain and inflammation. |
Soluble fibre from foods, or an ispaghula product where appropriate, may also help some people—particularly when constipation is prominent. It should be introduced gradually with adequate fluid because increasing fibre too quickly can worsen bloating.
Supporting the gut–brain connection
Movement, sleep and stress management are part of good IBS care. Regular physical activity can support bowel function and general wellbeing. Relaxation practices, cognitive behavioural therapy and gut-directed psychological therapies may also help, particularly when stress and symptom anxiety reinforce one another. This is not because the symptoms are imaginary; it reflects the genuine two-way relationship between the gut and brain.
Peppermint oil and other pharmacy treatments may ease particular symptoms, while prescribed options are available when first-line measures are insufficient. Suitability depends on the individual, other conditions and medicines, so advice from a pharmacist or GP is preferable to assembling a large collection of supplements.
A measured, individual approach
Effective IBS management is rarely about finding one perfect food or supplement. It is more often a process of confirming the diagnosis, noticing patterns, making one or two changes at a time and keeping the diet as varied as symptoms allow. A nutritional therapy practitioner can help a client organise observations and support balanced eating, while recognising when referral to a GP, dietitian or gastroenterology service is required.
Looking for personalised nutrition and lifestyle support? An FNTP member may be able to help you explore an approach suited to your individual needs. Find an FNTP practitioner.
This article is for general education and does not replace individual medical advice, diagnosis or treatment.
