Foods to Avoid With Crohn's Disease: What the Research Says and What to Track

Quick answer: No specific foods have been proven to cause or worsen Crohn's disease, according to NIDDK, and no diet has consistently been shown to reduce flares. What changes with Crohn's is the practical advice around flares and strictures: gastroenterology guidance suggests limiting hard-to-digest foods such as nuts, seeds and beans if you have a narrowing, and softer, well-cooked foods during a flare. Keep a food diary, avoid cutting whole food groups without advice, and involve a registered dietitian.

Crohn's disease can affect any part of the digestive tract, and eating can be painful, unpredictable and a worry. This guide sets out what NIDDK, the American Gastroenterological Association (AGA) and a major academic medical center say, with the limits of the evidence stated. It is general information, not medical advice.

What NIDDK Says

NIDDK says researchers have not found that specific foods cause or worsen Crohn's disease symptoms, and that your doctor may suggest a food diary to spot foods that seem to make symptoms worse. It explains why nutrition is affected: symptoms can reduce appetite, inflammation in the small intestine can limit nutrient absorption, and some medicines and surgeries can reduce absorption. It says studies suggest that healthy eating may lower the risk of developing IBD, that eating a variety of healthy foods can improve healthy gut bacteria, and that your doctor may recommend supplements if your body is not absorbing enough nutrients. Talk with your doctor before taking any vitamins or supplements.

What the AGA Advises

The AGA's 2024 clinical practice update on diet in IBD is an expert review, so it does not grade the evidence. It says that no diet has consistently been found to decrease the rate of flares in adults with IBD; that, unless there is a contraindication, patients should be advised to follow a Mediterranean diet; that patients should limit ultra-processed foods; and that dietary restrictions, along with the complications of IBD, can result in malnutrition. For patients with strictures, it recommends careful chewing and cooking, and processing fruits and vegetables to a soft, less fibrous consistency. It advises monitoring everyone with IBD for vitamin D and iron deficiency, and monitoring people with extensive ileal disease or prior ileal surgery for vitamin B12 deficiency.

If You Have a Stricture

A stricture is a narrowing of the bowel. UCSF Health says that if you have strictures it is especially important to avoid nuts, seeds, beans and kernels, and the AGA suggests careful chewing and cooking fruits and vegetables until soft. These foods can cause pain or a blockage when the passage is narrow, so your doctor's instructions override any general list. Severe abdominal pain, a swollen abdomen or repeated vomiting needs urgent medical attention.

During a Flare

• A low-residue diet to ease pain and diarrhea, limiting foods that increase stool output.
• Fewer fresh fruits and vegetables, prunes and caffeine for the duration of the flare.
• Less concentrated sugar from juice, candy and soda, and less alcohol.
• Smaller, more frequent meals, which are often easier to tolerate.
• A multivitamin with minerals, and liquid nutritional supplements if appetite is poor or solid food is hard to tolerate, as UCSF Health suggests. Ask your doctor first.

These are short-term measures. UCSF Health says to avoid foods only if they worsen your symptoms, to avoid overly restricting your diet, and to add fiber back gradually after a flare. The AGA also warns that dietary restrictions, along with the complications of IBD, can result in malnutrition.

Fat, Lactose and Other Specifics

• Fat: oily, foul-smelling stools can mean fat malabsorption, and a low-fat diet can help, so ask your doctor or dietitian.
• Lactose: if you are lactose intolerant, UCSF Health advises a lactose-free diet, and a breath hydrogen test can confirm it.
• Nutrients: the AGA advises monitoring vitamin B12 in people with extensive ileal disease or prior ileal surgery, and vitamin D and iron in everyone with IBD.
• Children: NIDDK says getting the right nutrients may help prevent malnutrition and problems with growth and development.

Ultra-Processed Food

The AGA's advice to limit ultra-processed foods is a pattern-level recommendation. It does not identify a single additive as a proven trigger. Our guides to how to avoid emulsifiers in food and food additives to avoid explain what appears on labels and what is known.

How to Find Your Own Triggers

1. Keep a food and symptom diary for a few weeks and share it with your doctor, as NIDDK suggests.
2. Change one thing at a time.
3. Avoid cutting whole food groups without advice, because restriction can lead to malnutrition.
4. Ask for a registered dietitian, especially with strictures, weight loss or many restricted foods.
5. Review the plan after a flare, a medicine change or surgery.

See our food diary app guide for what to log, and foods to avoid with ulcerative colitis for the related condition.

Checking Packaged Food With Foodsage

Foodsage is an ingredient checker. You can choose IBD as one of your conditions, add custom sensitivities such as dairy or FODMAP, and choose avoid categories such as artificial additives, added sugars and industrial seed oils, then scan a barcode or ingredient list and see which ingredients matched. It has a meal and symptom log, and it does not diagnose or treat Crohn's disease or tell you whether a food is safe with a stricture.

When to See a Doctor

Tell your care team about new or worsening symptoms, blood in your stool, unexplained weight loss, fever, or signs of dehydration, and get urgent care for severe pain, a swollen abdomen or repeated vomiting. This guide is general information, not medical advice.