Quick answer: During an IBS flare-up, eat small, regular meals built from simple foods your gut usually tolerates. Think plain cooked proteins like eggs, chicken or fish, rice, oats or potatoes, and well-cooked low-FODMAP vegetables like carrots or zucchini. For a few days, skip large fatty or spicy meals, alcohol, fizzy drinks, extra caffeine and high-FODMAP foods like onion and garlic. Keep drinking fluids. Don't skip meals or fast.
When a flare hits, the question isn't "what's the perfect IBS diet". It's "what can I eat today without making this worse?" Most people end up living on toast and hoping, then feel worse because they've barely eaten.
There's a better middle ground. This guide gives you a short, guideline-based plan for the next few days, adjusted for whether your flare is mostly diarrhea, constipation or bloating. It also shows how to turn each flare into a personal list of safe meals, so the next one is easier.
Key takeaways
- Keep meals small and regular, and eat slowly. The NHS advises not to skip or delay meals [1].
- Lean on foods that are low in FODMAPs and fat. Monash lists swaps like eggs, firm tofu, plain cooked meats, oats, rice-based pasta, potato, carrot and zucchini [2].
- Soluble fiber (like oats or psyllium) helps IBS more than insoluble fiber (like bran). Add it gradually [3][4].
- A flare diet is for days, not months. Long-term strict restriction should be planned with a dietitian [3][5].
What should you eat during an IBS flare-up?
Eat simple, familiar meals that are low in fat and low in FODMAPs, in smaller portions spread through the day. These foods are less likely to cause extra gas, water or speed in an already irritable gut.
Low-FODMAP swaps from Monash University are a good starting point [2]:
| Food group | Gentler choices during a flare (low-FODMAP options per Monash) | Often worth pausing for a few days (high-FODMAP per Monash) |
|---|---|---|
| Protein | Eggs, firm tofu, tempeh, plain cooked chicken, meat or fish | Most legumes, some marinated or processed meats |
| Grains | Oats, rice-based or corn pasta, quinoa, plain rice cakes, sourdough spelt bread | Wheat, rye or barley breads, cereals and snacks |
| Vegetables | Carrot, zucchini, eggplant, green beans, bok choy, cucumber, lettuce, potato | Onion, garlic, leek, asparagus, mushrooms, artichoke |
| Fruit | Kiwi, orange, mandarin, pineapple, strawberries | Apples, pears, mango, watermelon, cherries, dried fruit |
| Dairy | Lactose-free milk, hard cheeses, feta, brie | Regular cow's milk, ice cream, yogurt |
| Sweet things | Maple syrup, small amounts of dark chocolate | Honey, high-fructose corn syrup, sugar-free sweets |
Some portion sizes matter. For example, Monash's low-FODMAP serving of zucchini is about 65 g [2]. If you need exact serving sizes, use the Monash FODMAP app.
A sample flare day (one example, not a prescription):
- Breakfast: oatmeal made with lactose-free milk, topped with a few strawberries
- Snack: rice cakes with a little peanut butter
- Lunch: rice, scrambled eggs and steamed carrots
- Snack: a kiwi
- Dinner: baked fish or tofu, boiled potato and cooked zucchini
- Through the day: water or other non-fizzy, non-caffeinated drinks
What to eat by flare type
Adjust the basic plan to match your main symptom. IBS flares aren't all the same.
| Flare type | What tends to help | Notes |
|---|---|---|
| Diarrhea-predominant (Bristol 6–7, urgency) | Small, low-fat meals. Soluble-fiber foods like oats and potato. Steady fluids [1][3][4] | Replace fluids. If diarrhea is severe or lasts, see a doctor |
| Constipation-predominant (Bristol 1–2, straining) | Regular meals, plenty of fluids, soluble fiber such as oats or psyllium, increased slowly [1][3][4] | Increase fiber by about 2–3 g a day so it doesn't worsen gas [4] |
| Bloating and pain | Smaller portions. Eat slowly. Ease off high-FODMAP foods, fizzy drinks and sugar-free gum or sweets [1][2] | The ACG suggests peppermint oil for overall IBS symptoms [3]. Ask a pharmacist if it's right for you |
On fiber: the ACG guideline suggests soluble fiber, but not insoluble fiber, for overall IBS symptoms [3]. NIDDK notes that too much fiber at once can cause gas, so add it a little at a time [4].
What should you avoid during an IBS flare?
For a few days, step back from the foods and habits most often linked to worse IBS symptoms. The NHS lists these [1]:
- lots of fatty, spicy or processed food
- more than 3 portions of fresh fruit a day (a portion is 80 g)
- more than 3 cups of tea, coffee or other caffeinated drinks a day
- lots of alcohol or fizzy drinks
- eating too quickly, or delaying and skipping meals
From Monash's list, the high-FODMAP foods in the right-hand column above are the next things to pause, especially onion and garlic. They hide in sauces, soups, stock and seasoning mixes [2].
The goal is to calm things down, not to build a permanent ban list. Once you feel better, return to your normal range of foods. If you think a specific food triggered the flare, test it properly later. Our guide to IBS trigger foods explains how.
Should you stop eating during an IBS flare-up?
There's no good evidence that fasting helps an IBS flare, and skipping meals can backfire. The NHS advises against delaying or skipping meals [1]. Long gaps followed by one large meal can be harder on the gut than several small ones.
If you truly can't face food, sip fluids and try small amounts of something plain every few hours. Get medical help if you can't keep fluids down, you're dizzy or barely urinating, or diarrhea is severe.
Should I go low-FODMAP during a flare?
Borrowing low-FODMAP swaps for a few days is a reasonable short-term move. Starting the full low-FODMAP diet is different. Monash describes Step 1 as a 2–6 week phase done under a dietitian's supervision, followed by reintroduction [5]. The ACG warns that long-term over-restriction may lead to nutritional deficiencies [3]. If you want to try the full diet, see our low-FODMAP reintroduction tracker and talk to a dietitian.
Build your own safe-meal list
The most useful flare food list is your own. Every flare is a chance to record what you ate and how your gut responded, so next time you're not guessing.
Safe-meal list template:
| Meal | Eaten during a flare? | Symptoms in the next 6 hours (0–10) | Stool after (Bristol) | Keep on the list? |
|---|---|---|---|---|
Illustrative example (invented entries to show the method):
| Meal | Eaten during a flare? | Symptoms in the next 6 hours (0–10) | Stool after (Bristol) | Keep on the list? |
|---|---|---|---|---|
| Oatmeal with lactose-free milk | Yes, 3 times | 2, 2, 3 | 5, 4 | Yes |
| Rice, eggs, steamed carrots | Yes, 2 times | 2, 1 | 5 | Yes |
| Chicken noodle soup (store-bought) | Yes, once | 6 | 6, 6 | Retest; check the label for onion and garlic |
| Toast with jam | Yes, 2 times | 4, 5 | 6 | Unclear; try sourdough spelt instead |
After three or four flares you'll have a short list of reliable meals. Write it on the fridge or save it in your notes. This is the kind of note people on IBS forums say they wish they'd started sooner.
Logging flare meals in Get Regular
For ongoing records, explore the Get Regular food and symptom tracker. Check the current workflow, privacy information and access before entering sensitive information. A recorded association is a question to investigate, not a confirmed trigger.
When to see a doctor
Diet tweaks are for a flare of IBS you already know. Get medical advice promptly if you have [3][6][7]:
- blood in your stool, or black, tarry stool
- fever, vomiting, or you can't keep fluids down
- severe pain that doesn't ease after a bowel movement or passing gas
- diarrhea that wakes you at night
- unexplained weight loss
- a flare that's much longer or different from your usual pattern
- symptoms starting after 50, or a family history of colon cancer, inflammatory bowel disease or celiac disease
FAQ
Are bananas good for an IBS flare?
Many people tolerate them. Ripeness may matter for FODMAP content, so check the Monash app for serving guidance. If bananas are on your personal safe list, use them.
Is peppermint tea good for IBS?
The ACG guideline suggests peppermint (studied mainly as peppermint oil capsules) for overall IBS symptoms [3]. Peppermint tea is a gentle, low-risk drink many people find soothing, though it hasn't been studied the same way. Peppermint can worsen heartburn in some people.
Can I drink coffee during an IBS flare?
It's usually better to cut back for a few days, as caffeine can stimulate the bowel. The NHS suggests no more than 3 caffeinated drinks a day in general [1]. During a flare, decaf or one small cup may sit better.
How long should I eat bland food after a flare?
Only until symptoms settle, usually a few days. Then widen your diet again, adding back one or two foods at a time. A varied diet is better for long-term gut health and nutrition [3].
Sources
- NHS. Diet, lifestyle and medicines for IBS. https://www.nhs.uk/conditions/irritable-bowel-syndrome-ibs/diet-lifestyle-and-medicines/
- Monash University. Treating IBS with a 3-Step FODMAP Diet (info sheet). 2026. https://monashfodmap.com/documents/203/3-step_FODMAP_Diet_2026_A4_info_sheet.pdf
- Lacy BE, Pimentel M, Brenner DM, et al. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. Am J Gastroenterol. 2021;116(1):17–44. https://pubmed.ncbi.nlm.nih.gov/33315591/
- NIDDK. Eating, Diet, & Nutrition for Irritable Bowel Syndrome. https://www.niddk.nih.gov/health-information/digestive-diseases/irritable-bowel-syndrome/eating-diet-nutrition
- Monash University (Dwyer E). 3 Steps of the Low FODMAP Diet: Complete Guide. 2018. https://www.monashfodmap.com/blog/3-phases-low-fodmap-diet/
- NHS. Symptoms of irritable bowel syndrome (IBS). https://www.nhs.uk/conditions/irritable-bowel-syndrome-ibs/symptoms/
- Cleveland Clinic. Irritable Bowel Syndrome (IBS). https://my.clevelandclinic.org/health/diseases/4342-irritable-bowel-syndrome-ibs
This article is for general education and isn't medical advice. Get Regular is a tracking app. It doesn't diagnose or treat any condition. If you have red-flag symptoms or ongoing changes in your digestion, talk to a doctor.