Celiac Symptoms in Adults: Signs, Testing and Next Steps
Celiac disease in adults can show up as bloating, diarrhea and stomach pain. It can also show up as fatigue, an itchy rash, mouth sores, tingling in the feet, or no symptoms at all. The only way to know is to be tested while you are still eating gluten. This guide covers what to look for, what the symptoms can mean, and what happens when you ask a gastroenterologist to check.
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TL;DR
- Celiac symptoms vary widely and can come and go. In adults, digestive symptoms are less dominant than in children, so many cases look like something else.
- Common signs include bloating, gas, chronic diarrhea or constipation, abdominal pain, and unexplained weight loss. Less obvious ones include fatigue, anemia, joint pain, headaches, depression or anxiety, and an itchy blistering rash.
- Some adults have no symptoms, yet untreated celiac disease can still cause complications over time.
- Do not start a gluten-free diet before testing. It can make blood tests and biopsies unreliable.
- Testing usually starts with a blood test and may be confirmed with a small-intestine biopsy.
Table of Contents
- What celiac disease is, in plain terms
- Digestive symptoms of celiac disease in adults
- Symptoms outside the gut
- Celiac disease with no symptoms
- When to see a doctor
- How celiac disease is diagnosed
- Do not stop eating gluten before testing
- Celiac disease or something that looks like it?
- Our perspective
- Get evaluated in South Plainfield
- What to bring to your appointment
- What happens after a diagnosis
- FAQ
- Sources
What celiac disease is, in plain terms
Celiac disease is a chronic digestive and immune disorder. When you eat gluten, the protein found in wheat, barley and rye, your immune system attacks the lining of the small intestine. That lining is where your body absorbs nutrients, which explains why the symptoms reach so far beyond the stomach (NIDDK).
It is not the same as a food allergy, and it is not the same as simply feeling better when you skip bread. It is a condition with a defined diagnostic process, and it is managed with a strict, lifelong gluten-free diet once it is confirmed.
Digestive symptoms of celiac disease in adults
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) notes that symptoms differ from person to person, that a person may have several at once, and that they can come and go (NIDDK). The digestive symptoms it lists for adults include:
- Bloating and gas
- Chronic diarrhea
- Constipation
- Abdominal pain
- Nausea or vomiting
- Stools that are loose, greasy, bulky or foul-smelling
- Lactose intolerance caused by damage to the small intestine
MedlinePlus, from the National Library of Medicine, adds unexplained weight loss and decreased appetite to the adult list (MedlinePlus).
Why these symptoms are easy to dismiss
Every item on that list is also a symptom of something more common. Bloating and irregular bowel habits get blamed on stress, a sensitive stomach, or irritable bowel syndrome. Lactose intolerance is a good example: it can be a clue to celiac disease, because the damaged intestine stops making enough of the enzyme that digests milk sugar. An adult who has quietly cut out dairy for years may never have been asked why.
If your symptoms have lasted for weeks, keep returning, or simply never fully resolve, they deserve a proper workup rather than another round of guessing. Our guide to early signs of GI issues can help you decide what is worth raising.
Symptoms outside the gut
This is where adult celiac disease often hides. Because the small intestine is not absorbing nutrients well, and because the immune response is body-wide, problems can appear far from the digestive tract. NIDDK lists these among the less obvious signs (NIDDK):
- Fatigue
- Joint or bone pain
- Depression or anxiety
- Headaches
- Balance problems
- Seizures or peripheral neuropathy
- Reproductive problems
- Mouth symptoms such as canker sores
- Dermatitis herpetiformis, an itchy, blistering skin rash
MedlinePlus lists a similar set for adults, including iron-deficiency anemia, bone loss, missed menstrual periods, and tingling in the hands or feet (MedlinePlus).
Anemia, bone loss and tingling
These three share a logic. Iron-deficiency anemia can occur when the intestine cannot absorb iron. Bone loss can follow poor absorption of the nutrients bones depend on. Tingling in the hands or feet reflects nerve involvement. If you have been told you are anemic and nobody has found a cause, or a bone density scan came back lower than expected for your age, celiac disease is one of the things a gastroenterologist will consider.
The itchy rash: dermatitis herpetiformis
NIDDK describes dermatitis herpetiformis as an itchy, blistering rash that usually appears on the elbows, knees, buttocks, back or scalp. Among untreated adults with celiac disease, about 10% to 20% have it, and some people have the rash without other symptoms (NIDDK). A persistent, intensely itchy rash in those locations is worth mentioning to both a dermatologist and a gastroenterologist.
Can celiac disease cause depression?
Yes, it can be associated with it. NIDDK and MedlinePlus both list depression or anxiety among the possible non-digestive manifestations of celiac disease. That does not mean every adult with depression has celiac disease. It means that when low mood or anxiety arrives alongside digestive trouble, fatigue or the other signs above, the gut is worth looking at too.
Celiac disease with no symptoms
Adults can have celiac disease and feel essentially fine. NIDDK states that some people have no symptoms, yet untreated celiac disease can still lead to complications over time (NIDDK). This is why a family history matters. If a close relative has been diagnosed, tell your doctor even if you have no complaints, because NIDDK lists family history among the things clinicians review when they evaluate for the disease (NIDDK diagnosis).
Symptoms that fade, then return
Because symptoms come and go, many adults assume the problem has resolved. NIDDK notes that symptoms commonly improve or disappear on a gluten-free diet, and can return after even small gluten exposures. That pattern is part of why people who self-treat by cutting out gluten often end up confused: they feel better, but never learn whether they have celiac disease, a milder sensitivity, or something unrelated.
When to see a doctor
Make an appointment if any of these apply:
- Digestive symptoms such as diarrhea, bloating, pain or constipation last more than a few weeks or keep coming back.
- You are losing weight without trying.
- You have iron-deficiency anemia, bone loss, or tingling in the hands or feet without a clear cause.
- You have an itchy, blistering rash on the elbows, knees, buttocks, back or scalp.
- A parent, sibling or child has celiac disease.
Unexplained weight loss, blood in the stool, and trouble swallowing are signs to act on quickly, whatever the cause. Our list of digestive health red flags explains which symptoms should not wait.
How celiac disease is diagnosed
NIDDK says doctors diagnose celiac disease using medical and family history, a physical exam, blood tests and small-intestine biopsies. Blood tests usually come first, followed by a biopsy, and a skin biopsy or genetic testing may be added in some cases (NIDDK diagnosis).
The blood test
The American College of Gastroenterology guideline names the IgA anti-tissue-transglutaminase test as the preferred single test for detecting celiac disease in people older than two. Because some people have IgA deficiency, which can make that test misleading, total IgA should be measured when deficiency is possible, and IgG-based tests are used if it is found (ACG guideline). You do not need to memorize this. It simply means your doctor may order more than one blood marker, and that is normal.
Blood tests are a strong starting point, not a perfect one. We explain how a negative result can still leave questions open in our article on celiac test accuracy.
The biopsy
When blood work points toward celiac disease, the next step is typically an upper endoscopy. During this procedure, a gastroenterologist passes a thin, flexible camera through the mouth to the first part of the small intestine and takes small tissue samples. A pathologist then looks for the intestinal damage characteristic of celiac disease. If you are weighing this step, read about upper endoscopy (EGD) and how to prepare through our EGD preparation instructions.
Do not stop eating gluten before testing
This is the most common and most avoidable mistake. NIDDK says doctors do not recommend starting a gluten-free diet before diagnostic testing, because it can affect the results (NIDDK diagnosis). The American College of Gastroenterology gives the same advice: continue eating gluten during evaluation, since removing it can reduce the reliability of both blood tests and biopsy (ACG guideline).
In practice, that means a person who has already gone gluten-free for months may test negative and still have celiac disease. If that is you, do not just restart gluten on your own and hope for the best. Talk with a gastroenterologist first about whether a supervised gluten challenge makes sense. We lay out what to expect in our guide to the gluten challenge for celiac testing.
Celiac disease or something that looks like it?
Bloating and irregular stools do not always mean celiac disease. Several conditions overlap:
| Condition | What overlaps with celiac | How it is sorted out |
|---|---|---|
| Irritable bowel syndrome (IBS) | Bloating, gas, diarrhea, constipation, cramping | Celiac disease is typically ruled out first, then IBS is diagnosed based on symptom pattern |
| Non-celiac gluten sensitivity | Symptoms after eating gluten | Celiac disease is excluded by testing; see our guide to non-celiac gluten sensitivity testing |
| Inflammatory bowel disease (Crohn’s, colitis) | Diarrhea, abdominal pain, weight loss | Different tests, including stool markers and endoscopy; see screening tests for IBD |
| Lactose intolerance | Gas, bloating, diarrhea after dairy | Can be a standalone issue or a consequence of intestinal damage |
The overlap is the reason a guess is a poor strategy. The right treatment depends on the right diagnosis, and the diets for these conditions are not interchangeable.
Our perspective
Adults rarely walk into our office saying they think they have celiac disease. They come in because they are tired, bloated, anemic, or have been told for years that it is probably IBS. The pattern we try to catch is the one that was never connected: a digestive complaint, plus something that seems unrelated. Our approach is to listen to the full story first, including family history, then choose testing in the right order, with gluten still in your diet. A careful workup spares you from years of uncertainty and from a restrictive diet you may or may not need. Dr. Parikh is a board-certified, fellowship-trained gastroenterologist, and our care is built around the individual patient. We communicate in English, Gujarati, Hindi and Spanish, because describing symptoms clearly matters, and it is easier to do in the language you think in. Precision Digestive Health
Get evaluated in South Plainfield
If your symptoms sound familiar, we can help you work out whether celiac disease is the cause. Our practice offers celiac disease management, including evaluation, diagnostic testing, treatment planning and ongoing follow-up, with a board-certified gastroenterologist in South Plainfield, NJ.
If an endoscopy turns out to be part of your workup, or you need other digestive care, you can see everything we provide on our services page and schedule an appointment from there.
What to bring to your appointment
A little preparation makes the first visit more productive:
- A symptom timeline. Note when symptoms began, what makes them better or worse, and whether they come in waves.
- Your diet, as it is. Keep eating normally until you have been evaluated. Write down what you eat and any reactions.
- Family history. Celiac disease, autoimmune conditions, and bowel disease in relatives are all relevant.
- Prior results. Bring blood counts, iron studies, bone density scans, or earlier celiac tests.
- Medication and supplement list. Include anything for reflux, anemia or mood.
If you want broader context for what is normal and what is not, our overview of signs of healthy digestion is a good companion.
What happens after a diagnosis
Once celiac disease is confirmed, the treatment is a gluten-free diet. NIDDK notes that symptoms commonly improve or disappear on the diet, but can return after small amounts of gluten (NIDDK). Follow-up matters: it lets your care team check how you are responding, review nutrition, and address any symptoms that persist. That ongoing relationship is part of how we approach care.
FAQ
What are the first signs of celiac disease in adults?
There is no single first sign. Bloating, gas, diarrhea, constipation and abdominal pain are common, but so are fatigue, headaches, joint pain and mouth sores. Symptoms can come and go, which makes them easy to overlook.
Can you have celiac disease without digestive symptoms?
Yes. NIDDK says some people have no symptoms at all, and others have mainly non-digestive ones such as the itchy rash dermatitis herpetiformis. Untreated celiac disease can still lead to complications over time, so family history and unexplained findings like anemia matter.
Should I go gluten-free before I get tested?
No. Both NIDDK and the American College of Gastroenterology advise staying on gluten until testing is complete, because removing it can make blood tests and biopsies unreliable. If you have already stopped, ask a gastroenterologist how to proceed.
How is celiac disease tested?
Your doctor reviews your history, examines you, and orders blood tests. If those suggest celiac disease, a biopsy of the small intestine, taken during an upper endoscopy, usually confirms it. Skin biopsy or genetic testing is added in some cases.
Can celiac disease cause depression or anxiety?
It can. NIDDK and MedlinePlus both list depression or anxiety among the possible non-digestive effects. If mood changes appear alongside digestive symptoms or fatigue, mention all of it to your doctor.
Sources
- Symptoms & Causes of Celiac Disease, NIDDK
- Diagnosis of Celiac Disease, NIDDK
- Celiac Disease Screening, MedlinePlus
- American College of Gastroenterology Clinical Guideline on celiac disease
