Nutrition Guide: What foods to avoid during a flare up?

October 8, 2025 •

4 min read

According to the Crohn's & Colitis Foundation, many individuals with inflammatory bowel diseases (IBD) report that specific foods can worsen symptoms during a flare-up. Knowing what foods to avoid during a flare up is a critical step toward managing discomfort, promoting healing, and giving your gastrointestinal tract a much-needed rest.

Quick Summary

This guide covers specific food groups to eliminate or limit during a digestive flare, including high-fiber, fatty, spicy, and processed options. It details dietary adjustments for conditions like IBD, IBS, gastritis, and diverticulitis to alleviate symptoms.

Key Points

High-Fiber Foods: Limit insoluble fiber from whole grains, nuts, seeds, and raw produce during a flare to reduce gut irritation and stool bulk.
Fatty & Fried Foods: Avoid foods high in fat and fried items, as they are difficult to digest and can worsen diarrhea and abdominal pain.
Dairy Products: Cut back on high-lactose dairy like milk and cheese, especially if you have an intolerance, as it can cause bloating and diarrhea during a flare.
Caffeine & Alcohol: Steer clear of stimulants like caffeine and gut irritants like alcohol, which can increase bowel motility and inflammation.
Personalized Triggers: Use a food diary to track what you eat and identify your specific trigger foods, as dietary sensitivities vary greatly among individuals.
Focus on Low-Residue: Opt for soft, cooked, low-fiber foods like white rice, mashed potatoes, and lean poultry to give your digestive system a break during active symptoms.
Gradual Reintroduction: Reintroduce high-fiber foods slowly after a flare-up resolves to avoid new irritation and work toward a more balanced, long-term diet.

A flare-up is a period of heightened disease activity in chronic digestive conditions like Inflammatory Bowel Disease (IBD), Irritable Bowel Syndrome (IBS), gastritis, or diverticulitis. During this time, the lining of the digestive tract becomes inflamed and highly sensitive. While specific triggers vary by individual, and what works for one person may not work for another, there are general dietary principles to follow to avoid further irritation.

The General Dietary Strategy During a Flare-Up

When experiencing a flare-up, the primary goal is to minimize the workload on your digestive system. This often means moving toward a temporary, low-fiber, and bland diet that is easy to digest. The strategy is to consume foods that are less likely to scrape against an inflamed gut lining or produce excess gas and bloating. It is also crucial to stay well-hydrated, especially if experiencing diarrhea, to prevent dehydration. As symptoms improve, foods can be slowly and carefully reintroduced to determine individual tolerance.

Common Culinary Culprits: What Foods to Avoid During a Flare Up

Here are some of the most common food categories that tend to worsen symptoms during a flare-up across various conditions:

High-Fiber Foods (Insoluble Fiber)

During a flare, high-fiber foods can add significant bulk to stool and irritate an already sensitive gut lining. This is particularly true for insoluble fiber, which doesn't dissolve in water. While crucial for long-term health, it should be limited during active symptoms.

Whole Grains: Brown rice, whole wheat bread, oats, and quinoa.
Nuts and Seeds: Including popcorn, as they can be difficult to digest and may get caught in diverticula.
Raw Fruits and Vegetables: Especially those with tough skins and seeds, like apples, berries, and broccoli.
Legumes: Beans, lentils, and peas can produce gas and bloating.

Fatty and Fried Foods

High-fat foods are notoriously difficult for the digestive system to process, and during a flare, this can lead to worsened diarrhea and abdominal discomfort.

Fried foods: French fries, fried chicken, and donuts.
High-fat cuts of meat: Bacon, sausage, and fatty red meats.
Creamy sauces and gravies: Can be heavy on the digestive system.

Dairy Products

Many people with digestive conditions, especially IBD, experience temporary lactose intolerance during a flare-up, which can lead to bloating, gas, and diarrhea.

Milk, cheese, and ice cream: High-lactose dairy products are common culprits.
Alternatives: Opt for lactose-free products or plant-based milks fortified with calcium.

Spicy and Highly Seasoned Foods

The compounds that give spicy foods their kick, such as capsaicin, can directly irritate the gut lining and worsen symptoms like stomach pain and diarrhea.

Spicy sauces and peppers: Chili, cayenne, and hot sauces.
Curries and heavily spiced dishes: Can be too much for an inflamed system.

Caffeine, Alcohol, and Sugary Drinks

These liquids can stimulate bowel motility and further irritate an already inflamed gut. Sugary beverages can also pull excess water into the intestines, worsening diarrhea.

Caffeinated beverages: Coffee, tea, and energy drinks.
Alcohol: Beer, wine, and liquor.
Sugary drinks: Soda, fruit juices with added sugar, and sports drinks.
Sugar alcohols: Found in diet drinks and sugar-free candy (e.g., sorbitol, xylitol).

Processed and Refined Foods

Processed foods often contain additives, unhealthy fats, and refined sugars that can trigger inflammation. Opting for whole, unprocessed foods, even during a bland diet, is a safer bet.

Packaged snacks: Chips, cookies, and pastries.
Deli meats and processed sausages: Often contain additives and unhealthy fats.

Comparison of Flare-Friendly vs. Avoid-During-Flare Foods


Food Category	Flare-Up Friendly Options	Foods to Avoid During a Flare-Up
Grains	White bread, white rice, pasta, refined cereals (rice flakes, cornflakes)	Whole grains (brown rice, whole wheat bread), popcorn, high-fiber cereals
Fruits	Peeled and cooked fruits (applesauce, canned pears), bananas, melons	Raw fruits with skin/seeds, berries, dried fruit, citrus fruits
Vegetables	Cooked and peeled vegetables (carrots, potatoes without skin, squash), pureed soups	Raw vegetables, cruciferous vegetables (broccoli, cauliflower), onions, corn
Protein	Lean, tender cooked meat/poultry, fish, eggs, tofu	Fatty cuts of meat, fried meat, processed meat, beans, lentils
Drinks	Water, herbal tea, clear broths, low-sugar rehydration drinks	Alcohol, caffeine (coffee, tea, soda), carbonated drinks, sugary juices
Fats	Small amounts of smooth nut butters, olive oil	Fried foods, high-fat sauces, margarine

Finding Your Personal Triggers

Dietary management during a flare-up is a very personal process. What triggers symptoms for one person may be tolerated by another. To identify your specific trigger foods, health professionals often recommend keeping a food diary. This involves recording everything you eat and drink, along with any symptoms you experience. The insights gained can be invaluable for creating a long-term diet plan that minimizes flares. Consulting with a registered dietitian specializing in digestive health can provide expert, personalized guidance.

The Low-FODMAP Diet

For conditions like IBS and SIBO, a low-FODMAP diet is often used as a tool to identify triggers. FODMAPs are specific carbohydrates that can be poorly absorbed and cause gas, bloating, and diarrhea. This diet involves three phases: a strict elimination phase, followed by a reintroduction phase to test individual tolerance, and finally, a personalized maintenance phase. This process is highly effective for many, but should ideally be done with a healthcare provider's supervision to prevent nutritional deficiencies.

Conclusion

Managing a digestive flare-up effectively requires a strategic and temporary shift in dietary habits. By understanding what foods to avoid during a flare up—primarily high-fiber, fatty, spicy, and irritating beverages—you can help calm your digestive system and reduce symptoms. The key is to listen to your body, keep a food diary to identify personal triggers, and gradually reintroduce a wider variety of foods as you recover. While these dietary adjustments can be restrictive, they are a powerful tool for navigating active flare-ups and paving the way toward remission and long-term digestive wellness. A high-fiber diet is generally beneficial during remission to support overall bowel health. Crohn's & Colitis Foundation provides further educational resources on managing these conditions.

Frequently Asked Questions

A digestive flare-up is a period of increased or worsened symptoms for a person with a chronic digestive condition, such as Inflammatory Bowel Disease (IBD), Irritable Bowel Syndrome (IBS), or diverticulitis. It is characterized by active inflammation, abdominal pain, diarrhea, and other symptoms.

While diet does not cause underlying conditions like IBD, it can trigger or worsen symptoms during an active flare-up. Certain foods can irritate an already inflamed digestive tract, so avoiding specific triggers is a key management strategy.

Not necessarily all fiber, but it is wise to limit insoluble fiber during a flare-up, which is found in whole grains, nuts, seeds, and raw vegetables. Soluble fiber, found in foods like oatmeal and bananas, may be better tolerated and can help manage diarrhea.

During a flare-up, focus on clear fluids to stay hydrated. Good options include water, clear broths, herbal tea (chamomile or peppermint), and low-sugar electrolyte drinks. Avoid caffeine, alcohol, and carbonated beverages.

The low-FODMAP diet is a specific elimination diet that is most commonly recommended for managing Irritable Bowel Syndrome (IBS) and Small Intestinal Bacterial Overgrowth (SIBO). It may be helpful for some IBD patients, but it is not a universal solution and should be discussed with a doctor or dietitian.

After your symptoms subside, you can begin to slowly reintroduce foods. Start with well-tolerated, low-fiber options and add one or two items every few days while monitoring your symptoms. It is important to increase fiber gradually to avoid triggering another flare.

This is an outdated belief. While it was once thought nuts and seeds could get lodged in diverticula, modern research does not support this. However, during an active flare-up, it is still recommended to follow a temporary low-fiber diet, which includes avoiding nuts and seeds.