Crohn's Mouth Sores (Oral Signs of Crohn's and Ulcerative Colitis)
Crohn's mouth sores can look exactly like ordinary canker sores, or they can look like nothing you've seen before: lips that stay puffy for weeks, a bumpy, pebbled feel inside the cheek, or a long, sore split in the fold where the cheek meets the gum. People with ulcerative colitis get mouth ulcers too, usually the canker-sore kind. If you live with inflammatory bowel disease (IBD), or you're wondering whether your mouth is trying to tell you something, this page walks through what the signs look like and who to call.
Crohn's mouth sores are ulcers and other mouth changes caused by Crohn's disease, and less often by ulcerative colitis. They aren't contagious. Most IBD mouth sores look like canker sores and flare with the gut. Swollen lips, cobblestone cheek lining, and long ulcers in the cheek fold point more to Crohn's. A gastroenterologist diagnoses IBD. Your dentist treats the mouth. Get any sore that lasts past 2 weeks checked.
Not sure this is what you have? Answer five quick questions in our mouth spot checker. It compares what you see with more than 40 common conditions and tells you how soon to have it looked at.
- What do Crohn's mouth sores look like?
- Crohn's mouth sores vs. canker sores
- Ulcerative colitis mouth sores
- Other look-alikes
- Why Crohn's causes mouth ulcers
- IBD mouth symptoms
- Can mouth sores be the first sign?
- How long they last
- Who diagnoses Crohn's and UC
- Mouth care that helps
- Over-the-counter options
- What a dentist can do
- Dental visit tips if you have IBD
- Fewer flare-ups in the mouth
- Kids, pregnancy, and immune-suppressing medicine
- Doctor or dentist? When to call
- FAQ
What do Crohn's mouth sores look like?
Crohn's disease can affect any part of the digestive tract, from the mouth to the anus. The mouth is the very first stretch of that tract, so it's no surprise that it sometimes gets involved. What you see falls into two groups.
Signs that point toward Crohn's
These are less common, but when we see them, Crohn's is high on the list of possibilities:
- Lip swelling. One or both lips stay puffy and firm for weeks, sometimes with vertical cracks. The cheeks or face can swell too.
- Cobblestoning. The inside of the cheek turns swollen and bumpy, with creases between the bumps, a bit like a cobblestone street. It often doesn't hurt much.
- Deep linear ulcers. Long, narrow ulcers tucked into the fold where the cheek or lip meets the gum, often with raised, thickened edges on each side.
- Tissue tags. Small, soft flaps of tissue in that same fold or behind the back teeth.
- Swollen, red, grainy gums that go beyond normal gum irritation, sometimes called mucogingivitis.
Signs that can come with either Crohn's or ulcerative colitis
- Canker-like ulcers. Round, shallow, painful sores with a yellow-white center and red border, often showing up during a gut flare. These are the most common IBD mouth sores.
- Cracked corners of the mouth (angular cheilitis), often tied to low iron, B12, or other nutrients.
- A smooth, red, sore tongue (glossitis) from low B12, iron, or folate.
- White patches that wipe off, which is usually oral thrush brought on by steroids or immune-suppressing medicine.
- Dry mouth, bad breath, and taste changes, which people with IBD often report.
We don't have licensed photos of the Crohn's-specific signs, so the illustrations on this page show where they appear. The photos below show the more common signs people with IBD get. None of these photos are from patients with IBD. They show what the same kind of sore or change looks like in anyone.
Crohn's mouth sores vs. canker sores
This is the question we hear most. The honest answer is that a single Crohn's ulcer and an ordinary canker sore can be impossible to tell apart by looking. Canker sores are very common in everyone. A 2026 review that pooled 21 studies found that mouth ulcers weren't clearly more common in people with IBD than in people without it. So one canker sore, or even a habit of getting them, doesn't mean you have Crohn's.
What separates them is the pattern: where the sores sit, how they behave, and what else is going on in your body.
| Ordinary canker sore | Crohn's mouth sores | |
|---|---|---|
| Shape | Round or oval, shallow | Can be round and shallow, or long, narrow, and deep |
| Where | Inner lips, cheeks, sides of the tongue | Same spots, plus deep in the fold between cheek and gum |
| Other mouth changes | None | Sometimes lip swelling, cobblestone cheeks, tissue tags, grainy gums |
| How long | About 1 to 2 weeks | Canker-like ones about the same; Crohn's-specific changes can last weeks to months |
| Timing | Stress, minor injury, certain foods | Often worse during gut flares |
| Other symptoms | None | Diarrhea, belly pain, weight loss, fatigue, anemia, perianal problems |
| Biopsy | Rarely needed | Can show small clusters of immune cells (granulomas) typical of Crohn's |
Ulcerative colitis mouth sores and other IBD mouth signs
Ulcerative colitis mouth ulcers are usually the canker-sore type. They tend to come during flares and settle when the colitis is under control. The Crohn's-specific changes above (lip swelling, cobblestoning, tags) aren't expected with ulcerative colitis.
One rare condition leans toward ulcerative colitis: pyostomatitis vegetans. It shows up as many tiny yellow pustules on red, thickened lining that break open into shallow erosions, sometimes described as "snail tracks." It usually tracks with how active the colitis is.
Both forms of IBD can cause the deficiency signs (cracked corners, sore tongue), medication side effects like thrush, and dry mouth. Gum disease is also more common in people with either type, according to a 2025 analysis of 13 studies, so regular cleanings and good home care matter more than usual.
Other conditions that look like IBD mouth ulcers
Recurring mouth ulcers have a long list of possible causes. Several of them also involve the gut or the immune system, which is why your physician may test for more than one thing.
| Condition | What you may see in the mouth | Clues that point to it |
|---|---|---|
| Ordinary canker sores | Round, shallow ulcers, 1 to 2 weeks | Started in childhood or teens, otherwise healthy, no gut symptoms |
| Celiac disease | Canker-like ulcers, sore tongue, enamel defects on permanent teeth | Bloating, diarrhea, or anemia; symptoms tied to gluten |
| Behçet's disease | Frequent, often painful canker-like ulcers, sometimes many at once | Genital ulcers, eye inflammation, skin bumps |
| Low B12, iron, or folate | Smooth red tongue, cracked corners, ulcers | Fatigue, pale skin; can happen with or without IBD |
| Cold sores inside the mouth | Clusters of tiny blisters on the gums or hard palate | Tingling first, small sores that merge, history of cold sores |
| Orofacial granulomatosis | Lip and face swelling, cobblestoning, gum swelling | Looks like oral Crohn's but without gut disease (see below) |
| Medication ulcers | Ulcers or sores that start after a new drug | Methotrexate and some other medicines can cause them |
Orofacial granulomatosis
Orofacial granulomatosis is lip swelling, cobblestoning, and gum swelling that looks just like oral Crohn's on the outside and under the microscope, but without any known gut disease. Some people, especially children, are later found to have Crohn's, so a gastroenterology workup is often recommended. Food and additive sensitivities, such as cinnamon and benzoate preservatives, have been linked to it in some patients.
Why does Crohn's cause mouth ulcers?
There isn't one single reason. Several things can be going on at once:
- The disease itself. Crohn's is an immune-driven inflammation that can show up anywhere along the digestive tract. In the mouth, it can cause the same granulomas a gastroenterologist finds in the bowel.
- Flares. When the gut is inflamed, the immune system is more active everywhere, and canker-like ulcers often show up.
- Poor absorption. Crohn's in the small intestine, or surgery that removes part of it, can lower B12, iron, folate, and zinc. Those shortfalls cause sore tongues, cracked corners, and ulcers.
- Medications. Steroids raise the risk of thrush. Methotrexate can cause mouth ulcers. Drugs that calm the immune system can make mouth infections more likely.
- Less saliva and a sugary diet. Some medicines dry the mouth, and nutrition shakes and frequent small meals can feed cavities.
IBD mouth symptoms to watch for
- Mouth ulcers that come back, especially when your gut flares
- Lips or cheeks that stay swollen for more than a week or two
- A bumpy, thick, or pebbled feel inside the cheeks
- A painful split in the fold between your cheek or lip and your gum
- Gums that are red, swollen, and grainy, or bleed easily
- A tongue that's sore, burning, smooth, or redder than usual
- Cracks at the corners of the mouth that won't heal
- White patches that wipe off, or a cottony, bad taste
- Dry mouth, bad breath, or a change in how food tastes
Can mouth sores be the first sign of Crohn's?
Sometimes, yes. The mouth can show signs before anyone has looked at the gut. In one study of children being checked for IBD, a dentist found Crohn's-related mouth changes in about 4 in 10 of the children diagnosed with Crohn's. In 2 of them, the mouth biopsy was the only place the typical granulomas showed up. Their gastroenterologists had noticed the mouth changes in fewer than half of those children.
That said, canker sores alone are rarely the first sign of Crohn's. Mouth ulcers deserve a closer look when they come with:
- diarrhea, belly pain, blood in the stool, or unexplained weight loss
- slow growth or delayed puberty in a child
- lip swelling, cobblestoning, or tissue tags
- anemia or low B12 on bloodwork
If that sounds like you or your child, tell your physician. We can describe and photograph what we see in the mouth and send it along. The diagnosis itself comes from your doctor and the tests below.
How long do Crohn's mouth sores last?
It depends on the type:
- Canker-like ulcers usually heal in 1 to 2 weeks, like ordinary canker sores. They often come back with the next flare.
- Crohn's-specific changes such as lip swelling and cobblestoning can last weeks to months and wax and wane. Long-standing lip swelling can become firm and slow to go down.
- Deficiency signs like a sore tongue start improving within weeks once the missing nutrient is replaced.
- Thrush usually clears within 1 to 2 weeks of antifungal treatment.
Mouth signs often improve when the bowel disease is brought under control. Treating the gut is usually the biggest step for the mouth too.
Who diagnoses Crohn's and ulcerative colitis?
A gastroenterologist diagnoses IBD. Dentists don't, and no one can diagnose Crohn's from the mouth alone. What we can do is notice changes, write them down, photograph them, treat the mouth, and share what we find with your doctor.
| Who | What they do | Typical tests |
|---|---|---|
| Gastroenterologist | Diagnoses and treats Crohn's and ulcerative colitis | Blood tests (anemia, inflammation, nutrient levels), stool tests, colonoscopy with biopsies, upper endoscopy, capsule endoscopy, CT or MRI of the bowel |
| Primary care physician or pediatrician | Often orders first bloodwork and refers to a gastroenterologist | Complete blood count, iron, B12, folate, inflammation markers |
| Dentist | Notices and documents mouth changes, treats the mouth, coordinates care | Oral exam and photos; biopsy of a mouth lesion or referral for one |
| Oral surgeon or oral medicine specialist | Biopsies and manages hard-to-treat mouth disease | Biopsy, which can show granulomas typical of Crohn's |
A mouth biopsy that shows granulomas supports Crohn's but doesn't prove it. Your gastroenterologist puts it together with everything else.
Mouth care that helps with Crohn's and IBD mouth sores
Most of what helps an ordinary canker sore helps IBD mouth sores too. The aim is to keep the mouth clean and comfortable while your medical team gets the gut settled.
During a flare of mouth sores
- Rinse 3 or 4 times a day. Warm salt water (½ teaspoon of salt in a cup of water) or baking soda water (1 teaspoon in ½ cup). Swish and spit.
- Numb or cover sores before meals. A dab of numbing gel or a protective paste 10 to 15 minutes before eating makes food easier.
- Choose soft, cool, bland foods. Yogurt, eggs, oatmeal, mashed potatoes, smoothies without citrus. Use a straw.
- Skip what stings. Citrus, tomato, vinegar, spicy food, chips, crusty bread, and alcohol-based mouthwash.
- Keep brushing gently. A soft brush and a mild, SLS-free toothpaste. A clean mouth heals faster.
- Protect your lips. Plain petroleum jelly or an unflavored balm on dry, cracked lips and corners.
Every day
- Sip water through the day, especially if your medicines dry your mouth. Our dry mouth page has more ideas.
- Rinse with water after nutrition shakes or sweet snacks, and use a fluoride toothpaste twice a day.
- Keep a simple log of mouth sores next to your gut symptoms. Patterns help both your gastroenterologist and us.
Things to skip
- Don't hold aspirin or other pills against a sore. It burns the tissue.
- Don't stop or change your IBD medicine because of a mouth sore without talking to your gastroenterologist.
- Don't start a restrictive diet to fix mouth sores on your own, especially for a child. Talk with your doctor or a dietitian first.
Over-the-counter options for IBD mouth ulcers
| Type | What it does | Things to know |
|---|---|---|
| Numbing gels and liquids (benzocaine, lidocaine) | Short-term pain relief, handy before meals | Use as the label directs. Don't use benzocaine in children under 2. The FDA warns it can cause a rare, serious blood problem (methemoglobinemia). |
| Protective pastes, patches, and films | Cover the sore so food and teeth don't rub it | Dry the spot with a cotton swab first so it sticks |
| Alcohol-free antiseptic rinses | Help keep sores clean | Skip alcohol-based rinses. They sting and dry the mouth. |
| Acetaminophen | Overall pain relief | Follow the label. Ask your gastroenterologist before using ibuprofen or naproxen, since these can trigger flares in some people with IBD. |
| Saliva substitutes and xylitol gum or mints | Ease dry mouth | Helpful if your medicines dry your mouth |
| Petroleum jelly or plain lip balm | Protects cracked lips and corners | Cracks that don't heal in 2 weeks may need an antifungal, so have them checked |
If you're pregnant or nursing, check with your obstetrician before using medicated products.
What a dentist can do for Crohn's mouth sores
We don't treat Crohn's or ulcerative colitis. We do treat what's happening in the mouth, and we work alongside your physicians. As part of our care for medically complex patients, we can:
- Figure out what the sore is. We look at the shape, location, and pattern, check for a sharp tooth or appliance rubbing it, and photograph it so we can compare over time. Our oral medicine and diagnosis visits are set up for exactly this.
- Prescribe topical treatment. A steroid gel or rinse calms painful ulcers for many people. Numbing rinses help with eating.
- Treat thrush and cracked corners with antifungal medicine such as nystatin, clotrimazole troches, or fluconazole when needed.
- Remove the extra irritation. We can smooth sharp edges, repair broken fillings, and adjust dentures or night guards.
- Biopsy or refer for biopsy a lesion that doesn't behave like a canker sore, so it can be checked under a microscope.
- Suggest bloodwork through your physician for iron, B12, folate, and zinc if your mouth points that way.
- Keep your gums and teeth healthy with cleanings, gum care, and extra fluoride when dry mouth or diet raises cavity risk.
- Send notes and photos to your gastroenterologist, so mouth changes become part of your medical record.
Stubborn lip swelling or severe mouth disease sometimes needs steroid injections or medicine taken by mouth. When that happens, we coordinate with your gastroenterologist, an oral surgeon, or an oral medicine specialist.
Dental visit tips if you have Crohn's or ulcerative colitis
- Bring your medication list, including biologics, immune-suppressing drugs, and any steroids in the past year. These affect healing and infection risk.
- Tell us about steroids. Most routine dental care doesn't need any change. Before surgery or a long procedure, we'll check with your doctor.
- Antibiotics and pain relievers. Some antibiotics can upset IBD or lead to C. diff diarrhea, and anti-inflammatory pain relievers can trigger flares for some people. We prescribe them only when they're needed and are glad to check with your gastroenterologist.
- Plan around flares. If you're in a bad flare, routine work can usually wait. Pain, swelling, or infection shouldn't.
- Book the time that works for your gut. Many people do better at a certain time of day. Ask for a break anytime you need one.
- Mention anemia or low platelets, which can affect bleeding and healing.
- Bone medicines. Long-term steroid use sometimes leads to osteoporosis treatment, which matters before extractions. See osteoporosis medications and your dental health.
A thorough comprehensive dental exam once a year gives us a baseline, so new mouth changes are easier to spot.
Fewer flare-ups in the mouth
You can't prevent every mouth sore that comes with IBD, but these steps lower the odds and make the ones you get easier to deal with:
- Keep your IBD as well controlled as possible. Mouth signs often settle when the gut does.
- Stay on top of nutrient levels. Ask your physician about checking B12, iron, folate, vitamin D, and zinc, especially after bowel surgery.
- Use a soft brush and a mild, SLS-free toothpaste if you get canker-like sores often.
- Get sharp teeth and rough fillings fixed so they don't keep reopening sores.
- Treat thrush early if you're on steroids, and rinse with water after steroid inhalers if you use one.
- Keep up cleanings. People with IBD have more gum inflammation and gum disease.
- Don't smoke. Smoking makes Crohn's and gum disease worse.
Kids, pregnancy, and immune-suppressing medicine
Children and teens
In children, mouth signs of Crohn's can show up before the gut symptoms are obvious. Lip swelling, cobblestoning, or recurring ulcers in a child who is also tired, losing weight, not growing well, or having belly trouble should go to the pediatrician. For sore mouths: cool, soft foods, plenty of fluids, and children's acetaminophen as the label directs. No benzocaine under age 2.
Pregnancy
Pregnancy can change gum health and nutrient needs, and some IBD medicines are adjusted during pregnancy. Dental cleanings and needed treatment are safe and recommended while pregnant. Check with your obstetrician and gastroenterologist before starting any new medicated mouth product.
People on biologics, immune suppressants, or steroids
These medicines make mouth infections like thrush and cold sores more likely, and they can slow healing. Don't wait on a mouth infection, swelling, or a sore that's getting worse. Call us, and call your gastroenterologist if you also have a fever.
Crohn's mouth sores: call your doctor or your dentist?
Make a dental appointment if:
- A mouth sore hasn't healed in 2 weeks
- You have lip swelling, a bumpy cheek lining, or tissue tags that don't go away
- Sores keep coming back and you want a treatment plan or a prescription to keep at home
- You have white patches, cracked corners, or a sore tongue
- Your gums are swollen, bleed easily, or teeth feel loose
Call your gastroenterologist or physician too if:
- Mouth sores come with diarrhea, belly pain, blood in the stool, or weight loss
- Mouth sores are a new pattern for you, or your child has mouth sores plus poor growth or tiredness
- Mouth flares seem to line up with gut flares or a new medicine
Get care today if:
- You can't drink enough fluids because of mouth pain
- You have fever with mouth sores while on immune-suppressing medicine or biologics
- You have facial swelling that's spreading, or trouble swallowing or breathing (go to the ER)
- You have eye pain or redness, which can be a separate IBD or Behçet's problem that needs prompt care
A sore that doesn't heal, for any reason, should be looked at. Most turn out to be harmless, but persistent sores are one of the signs of oral cancer worth ruling out. Our guide to mouth ulcers covers other causes, and the autoimmune and systemic hub covers related conditions.
Crohn's and IBD mouth sores FAQ
Does Crohn's cause mouth sores?
Yes, it can. Crohn's disease can affect any part of the digestive tract, including the mouth. The most common Crohn's mouth sores look like canker sores and often appear during flares. Less often, Crohn's causes lip swelling, a cobblestone texture inside the cheeks, or long ulcers in the fold between the cheek and gum.
What do Crohn's mouth sores look like?
Many look like ordinary canker sores: round, shallow, with a yellow-white center and red border. Sores more typical of Crohn's are long and narrow, sitting in the fold where the cheek or lip meets the gum, with raised edges. Crohn's can also cause swollen lips with vertical cracks, bumpy cobblestone cheek lining, small tissue tags, and red, grainy gums.
Does Crohn's cause canker sores?
Crohn's can cause ulcers that look and act like canker sores, especially during flares. But canker sores are common in everyone, so having them doesn't mean you have Crohn's. They're more worrying when they come with diarrhea, belly pain, weight loss, or anemia.
Why does Crohn's cause mouth ulcers?
Several things combine. Crohn's inflammation can affect the mouth directly, and flares make the immune system more active everywhere. Poor absorption of B12, iron, folate, and zinc can cause ulcers and a sore tongue. Medicines like steroids and methotrexate can also cause thrush or ulcers.
Does ulcerative colitis cause mouth sores?
Yes. Ulcerative colitis mouth sores are usually the canker-sore type and tend to show up during flares. A rare condition called pyostomatitis vegetans, with tiny yellow pustules that break into shallow erosions, is more closely linked to ulcerative colitis. Swollen lips and cobblestoning are more typical of Crohn's than of ulcerative colitis.
Can mouth sores be the first sign of Crohn's?
Sometimes. In children especially, mouth changes like lip swelling, cobblestoning, or recurring ulcers can show up before gut symptoms are obvious. Most mouth sores are not a sign of Crohn's, though. If yours come with gut symptoms, weight loss, poor growth, or anemia, see your physician for testing.
Are Crohn's mouth sores contagious?
No. Crohn's and ulcerative colitis aren't infections, and their mouth sores can't spread to anyone. The exception is a separate infection that happens alongside IBD, like a cold sore from the herpes virus, which is contagious.
How do you treat Crohn's mouth sores?
Getting the gut disease under control is usually the biggest help. For the mouth itself, salt-water rinses, protective pastes, numbing gels, and soft, bland foods ease the pain. A dentist can prescribe a steroid gel or rinse, treat thrush, and fix sharp teeth that keep reopening sores. Low B12, iron, or folate should be checked and replaced through your physician.
Can Crohn's affect your tongue?
Yes, usually indirectly. Crohn's can lower B12, iron, and folate, which makes the tongue smooth, red, sore, or burning. Ulcers can form on the tongue too, and steroids can lead to white thrush patches on it. A blood test ordered by your physician can show whether a nutrient is low.
What is orofacial granulomatosis?
Orofacial granulomatosis is swelling of the lips and face, often with cobblestoning and gum swelling, that looks like oral Crohn's but happens without known gut disease. A biopsy shows the same granulomas seen in Crohn's. Some people, especially children, are later diagnosed with Crohn's, so a gastroenterology checkup is often recommended.
Can a dentist tell if you have Crohn's disease?
No. A dentist can't diagnose Crohn's. Dentists sometimes notice mouth changes that suggest it, like lip swelling, cobblestoning, or linear ulcers, and can biopsy or refer for a biopsy. The diagnosis comes from a gastroenterologist using blood and stool tests, colonoscopy with biopsies, and imaging.
Do Crohn's medications cause mouth problems?
Some do. Steroids raise the risk of thrush. Methotrexate can cause mouth ulcers. Biologics and other immune-suppressing drugs make infections like thrush and cold sores more likely. Some medicines also cause dry mouth or a metallic taste. Don't stop a medicine on your own; tell your gastroenterologist and your dentist.
Does Crohn's affect your gums and teeth?
It can. Gum disease is more common in people with Crohn's and ulcerative colitis. Crohn's can also cause swollen, red, grainy gums. Dry mouth from medicines and frequent sugary nutrition drinks can raise cavity risk, so regular cleanings and fluoride help.
Living with Crohn's or colitis and dealing with mouth sores?
If you're in the Jacksonville area and mouth sores, lip swelling, or a sore tongue keep coming back, we're glad to take a look, treat the mouth, and share what we find with your gastroenterologist. Dr. Henley regularly works with patients who have complex medical conditions.
Related conditions
Sources
- Lankarani KB, Sivandzadeh GR, Hassanpour S. Oral manifestation in inflammatory bowel disease: a review. World J Gastroenterol. 2013;19(46):8571–8579.
- Muhvić-Urek M, Tomac-Stojmenović M, Mijandrušić-Sinčić B. Oral pathology in inflammatory bowel disease. World J Gastroenterol. 2016;22(25):5655–5667.
- Harty S, Fleming P, Rowland M, et al. A prospective study of the oral manifestations of Crohn's disease. Clin Gastroenterol Hepatol. 2005;3(9):886–891.
- Scocca V, Sarnelli G, Pesce M, et al. Oral manifestations in patients with inflammatory bowel disease: a systematic review and meta-analysis. Dent J (Basel). 2026;14(5):250.
- Ayati A, Khodabandelu S, Khaleghi S, et al. A systematic review and network meta-analysis of the association between periodontitis and inflammatory bowel diseases. BMC Oral Health. 2025;25(1):463.
- National Institute of Diabetes and Digestive and Kidney Diseases. Diagnosis of Crohn's disease. NIH.
This page is for general education and isn't a diagnosis. Every mouth is different. If you have a sore you're worried about, see your dentist or physician. Photos marked Wikimedia Commons are used under their listed licenses and may have been cropped or resized.