What to eat during an ulcerative colitis flare

When UC symptoms spike — more diarrhea, cramping, urgency, and blood — what you eat becomes especially important. The inflamed gut is more sensitive and has less capacity to process difficult foods. Eating the wrong things can increase discomfort and bowel frequency; eating thoughtfully can help reduce stress on an already irritated digestive system.

This guide covers what tends to help and hurt during a flare, and what to focus on to keep your nutrition up while your gut is struggling. For a broader guide to eating with UC in remission as well, see our full ulcerative colitis diet guide.

The goal of eating during a flare

The goal is not perfection — it is minimizing gut irritation while staying nourished and hydrated. During a severe flare, you may have a reduced appetite, which is normal. Forcing yourself to eat large meals can worsen cramps and urgency.

Focus on:

• Small, frequent meals rather than three large ones
• Soft, low-residue foods that require less gut work
• Staying hydrated
• Not skipping meals entirely, even if appetite is low

Foods that tend to be better tolerated during a flare

Cooked, well-softened vegetables

Raw vegetables are too high in insoluble fiber during a flare. Switch to:

• Peeled, well-cooked carrots
• Peeled, mashed or boiled potatoes
• Cooked zucchini or squash (without seeds)
• Cooked green beans (no skins)
• Butternut squash, steamed and soft

Avoid: raw salads, broccoli, cabbage, cauliflower, corn, onions, peppers.

Refined grains and starches

Lower-fiber, refined carbohydrates are easier to digest during active inflammation:

• White rice (plain, well-cooked)
• Plain white bread or toast
• Plain crackers (like saltines)
• Plain pasta or white-flour noodles
• Plain oatmeal (cooked soft, not loaded with seeds or dried fruit)
• Plain boiled or mashed potato (no skin)

Avoid: whole grain breads, high-fiber cereals, brown rice, bran products.

Lean proteins

Protein is important for healing but should come from easy-to-digest sources:

• Skinless chicken breast (baked, boiled, or lightly sautéed)
• White fish (cod, tilapia, flounder) — baked or steamed
• Eggs (scrambled, boiled, or poached — not fried)
• Firm tofu (plain)
• Smooth nut butters (if tolerated) — peanut butter in small amounts

Avoid: red meat, processed meats, fried or fatty meats, spicy sausages.

Soft fruits (ripe and peeled)

• Ripe banana (one of the most universally tolerated fruits during a flare)
• Canned peaches or pears in juice (no skin)
• Cooked applesauce (unsweetened)
• Ripe melon (no rind)

Avoid: citrus fruits, berries with seeds, dried fruit, raw apple with skin.

Broths and soups

• Clear chicken or vegetable broth — helps with hydration and provides some electrolytes
• Low-fat soup with soft noodles and soft vegetables
• Bone broth (many people find this soothing)

Dairy — with caution

Whether to include dairy depends on individual tolerance. Some people with UC also have lactose sensitivity; others tolerate it fine.

• Low-fat yogurt may be tolerated by some
• Probiotic yogurt is popular though evidence for it in UC is not definitive
• Cheese in small amounts (especially aged, lower-lactose cheeses) may be fine for some

If you suspect dairy worsens your symptoms, eliminate it during the flare and reintroduce after.

Foods to avoid during a flare

These tend to worsen symptoms for most people during active disease:

Staying hydrated during a flare

Diarrhea causes significant fluid and electrolyte loss. Dehydration during a flare can make UC symptoms worse and leave you feeling exhausted.

• Drink water consistently throughout the day
• Oral rehydration solutions (Pedialyte, Liquid IV, or similar) help replace electrolytes lost through diarrhea
• Diluted fruit juice (no citrus), herbal teas, and clear broths count toward fluid intake
• Avoid caffeinated drinks, alcohol, and sugary sodas which can worsen dehydration

Signs of dehydration: dark urine, dizziness, dry mouth, feeling very weak. If you cannot keep fluids down or are severely dehydrated, seek medical attention.

Eating when you have no appetite

During a severe flare, food may be the last thing on your mind. Small, low-irritation options that require minimal effort:

• Plain crackers with peanut butter or a thin spread of cream cheese
• Banana
• Plain oatmeal
• Small bowl of white rice
• Clear soup or broth

Even small amounts of nutrition help support your body’s healing process. If you are unsure what triggered this flare, our guide on understanding a UC flare-up covers common triggers and how flares are assessed by your doctor.

Questions to ask your GI doctor

• Should I see a registered dietitian who specializes in IBD to get personalized guidance?
• Am I at risk of any nutritional deficiencies — iron, vitamin D, or B12 — from this flare?
• Are there any supplements I should be taking while my symptoms are active?
• Is my current weight loss during this flare a concern?
• What signs related to my nutrition should prompt me to call your office?
• Once I recover from this flare, are there any dietary restrictions I should maintain?

When to contact a doctor

Contact your healthcare provider if during a flare:

• You are unable to eat or drink for more than 24 hours
• You are losing weight rapidly
• You are showing signs of dehydration
• Your symptoms are worsening despite dietary changes

Dietary adjustments are supportive — they do not replace medical treatment for a UC flare. If symptoms are severe or worsening, contact your gastroenterologist.

This content is for educational purposes only. It does not replace personalized advice from a registered dietitian or your healthcare team.