If you live with IBS, you know it isn't constant. There are calm weeks when you barely think about your gut, and then there are flare-ups, days when pain, bloating and unpredictable bowel habits take over. That pattern is normal for IBS: symptoms characteristically come and go over time.1
What Does an IBS Flare-Up Feel Like?
A flare-up is a period when your usual IBS symptoms become more intense or more frequent. The core symptoms of IBS are abdominal pain linked to bowel movements, together with changes in stool form or frequency, and often bloating.2 During a flare you might notice:
- Cramping or aching abdominal pain, often eased after a bowel movement
- Bloating or a visibly swollen stomach
- Diarrhea, urgency, constipation, or swings between them
- Excess gas
- Fatigue and lower mood, which often travel with gut symptoms
How Long Does an IBS Flare-Up Last?
There's no fixed length. Some flares settle within hours; others last several days or longer. Over months, symptoms fluctuate, and many people move between IBS subtypes over time.1 Tracking your flares (when they start, what came before them and how long they last) is the most reliable way to learn your own pattern. Our guide to keeping an IBS food diary shows how.
Common Flare-Up Triggers
- Food. Most people with IBS link at least one food to their symptoms. In one study, 84% did, most often fatty or fried foods (52%) and dairy (49%).3 FODMAPs are a common driver; see our guide to IBS foods to avoid.
- Stress. The gut and brain are tightly connected, so a stressful week can show up as gut symptoms. Read more in our guide to the gut-brain connection and IBS.
- Poor sleep. People with IBS who woke more often during the night reported worse abdominal pain and gut distress.4
- Alcohol. In a diary study of women with IBS, binge drinking was linked to worse gut symptoms the next day.5
- Hormonal changes around your period can also make symptoms worse for some people.
What to Eat During an IBS Flare
When your gut is reactive, keep meals small, simple and low in FODMAPs:
- Simple carbohydrates: rice, potatoes, oats
- Plain proteins: chicken, eggs, fish, firm tofu
- Well-cooked low FODMAP vegetables: carrot, green beans, spinach
- Gentle fruit in small portions: kiwi, blueberries
- Plenty of water, especially if you have diarrhea
Go easy on fatty or fried meals, large portions, caffeine, alcohol and high FODMAP foods like garlic and onion until things settle. For a full week of flare-friendly meals, see our 7-day low FODMAP meal plan. Over the longer term, the low FODMAP diet is the dietary approach with the strongest evidence for IBS symptoms.9
Other Things That May Help
- Peppermint oil. US guidelines suggest peppermint oil may help global IBS symptoms7, though the overall benefit in research is small.6
- Gentle movement such as walking, and a warm compress on the abdomen, which many people find soothing.
- Calming the nervous system with slow breathing or a short walk outside.
Talk to a doctor or pharmacist before starting supplements or over-the-counter medicines, especially if you take other medication.
When to See a Doctor
A flare-up feels like your usual IBS, just more intense. Some symptoms are not typical of IBS and need medical assessment.8 Contact a doctor if you have:
- Blood in your stool or black, tarry stools
- Unintended weight loss
- Symptoms that wake you from sleep
- New symptoms starting after about age 50
- Fever, or signs of anemia such as unusual tiredness
- A family history of bowel cancer, inflammatory bowel disease or celiac disease
Also see a doctor if your symptoms change significantly from your usual pattern, or if flares are becoming more frequent.
