The main signs that point to celiac disease
Celiac disease causes your immune system to damage your small intestine when you eat gluten, a protein found in wheat, barley, and rye. The damage prevents your body from absorbing nutrients properly, which creates a range of symptoms. The most common ones are chronic diarrhea, bloating, stomach pain, and weight loss — but celiac disease can also show up as fatigue, anemia, bone pain, or skin rashes. Some people have only one or two symptoms; others have many.
The tricky part is that celiac disease mimics other conditions. Diarrhea and bloating could be irritable bowel syndrome, lactose intolerance, or dozens of other things. That is why you cannot diagnose yourself based on symptoms alone — you need blood tests and sometimes a biopsy to know for certain.
If you have been having stomach problems, feeling unusually tired, or noticing other symptoms that do not go away, the first step is to see your primary care doctor. Tell them specifically what you have noticed and for how long. They can order the tests that will either point toward celiac disease or rule it out.
Key Takeaways
- Celiac disease causes digestive symptoms like diarrhea, bloating, and stomach pain, but also fatigue, anemia, and skin problems in some people.
- You cannot diagnose celiac disease from symptoms alone — your doctor must order blood tests to check for specific antibodies your body makes in response to gluten.
- If the blood test is positive, your doctor will usually recommend an endoscopy with a biopsy to confirm the diagnosis by looking at intestinal damage.
- You must continue eating gluten while being tested, because stopping it beforehand will make the tests unreliable.
Blood tests that detect celiac disease
The first test your doctor will order is a serology test, which looks for antibodies — proteins your immune system makes when it reacts to gluten. The main ones doctors check for are tissue transglutaminase (tTG) and endomysial antibodies (EMA). If you have celiac disease and are eating gluten, these antibodies will be present in your blood.
Your doctor may also test for total immunoglobulin A (IgA) levels at the same time. A small number of people with celiac disease do not make enough IgA, which can make the standard tests unreliable. If your IgA is low, your doctor will use a different antibody test instead.
The blood test is straightforward — a nurse draws a small sample from your arm, and results usually come back within a week or two. A positive result does not automatically mean you have celiac disease, but it means your doctor will want to do more testing.
The endoscopy and biopsy that confirm the diagnosis
If your blood test is positive, your doctor will refer you to a gastroenterologist — a specialist in digestive system disorders. They will perform an upper endoscopy, a procedure where a thin tube with a camera is passed down your throat and into your small intestine. This lets the doctor see the intestinal lining directly.
During the endoscopy, the doctor takes tiny tissue samples (a biopsy) from your small intestine. These samples are examined under a microscope to look for the specific damage that celiac disease causes — flattened villi, which are the finger-like structures that normally absorb nutrients. If the biopsy shows this damage, celiac disease is confirmed.
The endoscopy takes about 15 to 30 minutes. You will be given sedation so you do not feel pain, though you may feel pressure or mild discomfort. Most people go home the same day and can return to normal activities within 24 hours.
Why you must keep eating gluten during testing
This is one of the most important things to understand: do not stop eating gluten before your tests. If you cut gluten out of your diet, your immune system will stop making the antibodies that the blood test detects. Your intestines will also begin to heal, so the biopsy may not show the damage that confirms celiac disease. Either way, your tests could come back negative even though you have the condition.
You need to eat gluten-containing foods regularly — bread, pasta, cereals, or anything with wheat, barley, or rye — for at least a few weeks before your blood test. Your doctor will tell you exactly how long. If you have already stopped eating gluten before seeing your doctor, tell them so they know to interpret your results carefully.
Symptoms that appear in children
Children with celiac disease often have different symptoms than adults. The most common are failure to thrive (not growing or gaining weight normally), chronic diarrhea, and a swollen belly. Some children become irritable, have delayed puberty, or develop dental enamel problems.
In young children, celiac disease symptoms often start after they begin eating solid foods containing gluten, usually between 6 months and 2 years old. If your child has ongoing digestive problems, is not growing as expected, or seems unusually tired, mention celiac disease to your pediatrician. The testing process is the same as for adults — blood tests first, then an endoscopy with biopsy if needed.
Other conditions that can look like celiac disease
Non-celiac gluten sensitivity causes similar symptoms — bloating, diarrhea, fatigue — but blood tests and biopsies are normal. Your doctor diagnoses it by ruling out celiac disease first, then seeing whether your symptoms improve when you stop eating gluten.
Wheat allergy is different from celiac disease. It causes an allergic reaction (itching mouth, swelling, hives, or anaphylaxis) that happens quickly after eating wheat. Blood tests for wheat allergy are different from celiac tests, and the condition does not damage the intestines the way celiac disease does.
Lactose intolerance causes bloating and diarrhea after eating dairy products, but it is not an immune reaction and does not damage the intestines. If you suspect lactose intolerance, your doctor can test for it separately.
What happens after diagnosis
If your biopsy confirms celiac disease, your doctor will refer you to a dietitian who specializes in celiac disease. The only treatment is a gluten-free diet — avoiding all foods and drinks that contain wheat, barley, rye, or their derivatives. This stops your immune system from attacking your intestines, allows the damage to heal, and relieves your symptoms.
Your doctor will also check your nutrient levels, because celiac disease often causes deficiencies in iron, calcium, vitamin D, and B vitamins. You may need supplements while your intestines heal and begin absorbing nutrients normally again. Most people feel significantly better within a few weeks of starting a gluten-free diet.
Frequently Asked Questions
Can I have celiac disease if my blood test is negative?
It is possible but uncommon. A small percentage of people have a form called seronegative celiac disease, where blood tests are negative but the biopsy shows intestinal damage. If your symptoms strongly suggest celiac disease but your blood test is negative, tell your doctor — they may still recommend an endoscopy to be certain.
How long does it take to get a diagnosis?
The blood test results usually come back within one to two weeks. If it is positive, your gastroenterology appointment may take another two to four weeks to schedule, and the endoscopy itself takes about 15 to 30 minutes. From first doctor visit to confirmed diagnosis typically takes four to eight weeks.
Will my symptoms go away once I stop eating gluten?
Most people feel better within days or weeks of eliminating gluten, though it varies. Your intestines need time to heal — usually three to six months for most of the damage to repair. Some symptoms like fatigue may take longer to resolve if you were severely deficient in nutrients.
Can celiac disease develop later in life?
Yes. While many people have symptoms starting in childhood, celiac disease can appear at any age, even in people who have eaten gluten their whole lives without problems. Stress, pregnancy, surgery, or infection can sometimes trigger it in people who were previously unaffected.
Do I need to test my family members?
Celiac disease runs in families — your relatives have a higher risk of having it. Talk to your doctor about whether your parents, siblings, or children should be tested. They may not have symptoms yet but could still have the condition.