What an IBS flare-up feels like
- Abdominal pain or cramping, often relieved by opening the bowels.
- Bloating and a swollen tummy; see why am I so bloated.
- Wind and rumbling.
- Diarrhoea, constipation or alternating between the two.
- Urgency and mucus in the stool.
- Tiredness, nausea, backache and bladder symptoms.
How long a flare lasts
IBS flares vary from a few hours to several days, and sometimes weeks. Some people notice a pattern, such as flares before periods or during stressful times. Keeping a symptom diary helps identify patterns and triggers.
Common food triggers
- Large, fatty or spicy meals.
- High FODMAP foods: onion, garlic, wheat, beans, lentils, apples, pears, milk and some sweeteners.
- Caffeine, alcohol and fizzy drinks.
- Artificial sweeteners such as sorbitol and xylitol.
- Eating quickly or irregularly.
See low FODMAP vegetables and low FODMAP diet for beginners.
Other triggers
- Stress and anxiety, which affect the gut-brain axis.
- Poor sleep.
- Menstrual cycle changes.
- Gastrointestinal infections.
- Antibiotics and some other medicines.
- Travel and changes to routine.
What to eat during a flare
- Small, regular meals rather than large ones.
- Plain, easy-to-digest foods: rice, oats, potatoes, eggs, plain chicken or fish, carrots, courgette.
- For diarrhoea: limit insoluble fibre such as bran and skins, and drink plenty of fluids.
- For constipation: gradually increase soluble fibre such as oats and linseeds, and drink water.
- Avoid known trigger foods until the flare settles.
See diet for IBS and bland diet foods.
Quick relief tips
- Apply a warm hot-water bottle or heat pack to the tummy.
- Try peppermint oil capsules, which can ease cramps.
- Sip peppermint or ginger tea.
- Go for a gentle walk to help move gas.
- Practise slow breathing or relaxation; see deep breathing for anxiety.
- Rest and avoid rushing meals.
Medicines that may help
- Antispasmodics such as mebeverine or hyoscine for cramps.
- Loperamide for diarrhoea.
- Soluble fibre supplements or osmotic laxatives for constipation.
- Low-dose antidepressants, prescribed by a doctor, for persistent pain.
Ask a pharmacist or doctor which options suit you.
Reducing future flares
- Keep a food and symptom diary.
- Try a low FODMAP diet with a dietitian, followed by reintroduction.
- Eat regular meals and take time to eat.
- Exercise regularly.
- Manage stress with therapy, mindfulness or gut-directed hypnotherapy.
- Get enough sleep.
The gut-brain connection
The gut and brain communicate constantly. Stress can increase gut sensitivity and change bowel movements, and IBS symptoms can increase anxiety. Psychological therapies such as cognitive behavioural therapy and gut-directed hypnotherapy are recommended for people whose symptoms persist despite diet and medicines.
A flare-day plan
- Have a list of “safe” meals you tolerate well.
- Keep peppermint capsules, a heat pack and any prescribed medicines at hand.
- Plan rest and reduce commitments where possible.
- Know where toilets are when going out if urgency is a problem.
- Use relaxation or breathing exercises when pain starts.
- Note the flare in your diary, including food, stress, sleep and cycle.
Fibre during a flare
Fibre can help or hinder depending on your symptoms. Soluble fibre, found in oats, linseeds and psyllium, is gentle and helps both diarrhoea and constipation for many people. Insoluble fibre, found in bran, skins and seeds, may worsen bloating and diarrhoea during a flare. Introduce changes gradually and drink plenty of water.
Flares when travelling
Travel often disrupts meals, sleep, hydration and toilet routines, which can trigger flares. Packing safe snacks, keeping regular meal times where possible, drinking enough water, walking during long journeys and carrying any medicines you rely on all help. For constipation, a small dose of soluble fibre or a laxative may be useful while away.
When to see a doctor
- Blood in the stool or black stools.
- Unexplained weight loss.
- Symptoms that wake you at night.
- Fever or vomiting.
- New or changed bowel habits after age 50.
- A family history of bowel cancer, coeliac disease or inflammatory bowel disease.
Key points to remember
- IBS flares cause worsening pain, bloating and bowel changes.
- Food, stress, sleep and hormones are common triggers.
- Small plain meals, heat, peppermint and relaxation help.
- Red-flag symptoms need medical assessment.
Questions about IBS flare-ups
These answers are general information and do not replace an examination or individual medical advice.
How long does an IBS flare-up last?
From a few hours to several days, and sometimes weeks.
What should I eat during an IBS flare-up?
Small, plain meals such as rice, oats, potatoes, eggs and plain fish or chicken.
Can stress cause an IBS flare-up?
Yes. Stress is one of the most common triggers.
What helps IBS pain fast?
Heat, peppermint oil, gentle walking and antispasmodic medicines can help.
Can IBS flare-ups cause fatigue?
Yes. Tiredness is common during flares.
Is coffee bad for IBS?
Caffeine can trigger symptoms in some people.
Should I fast during an IBS flare?
Not usually. Small regular meals are better than skipping meals.
Can periods trigger IBS flare-ups?
Yes. Hormonal changes around periods often worsen IBS symptoms.
Do probiotics help IBS flare-ups?
Some people find certain probiotics help; try one for about 4 weeks and stop if there is no benefit.
Sources
- NHS · Irritable bowel syndrome (IBS)
- NICE CG61 · Irritable bowel syndrome in adults: diagnosis and management
- Monash University · FODMAP food list
This guide is for general information and does not replace medical advice. How a problem is diagnosed and treated depends on your examination and medical history. If you think you have an emergency, contact your local emergency services.