Gluten Free Guerrillas
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What does a 'false negative' result with a coeliac blood test mean?

I was given my blood test results this morning by the receptionist at our surgery - I have to wait another week until I get to see a doctor to actually find out more details and she just read out to me what she could see on the screen.

I have been getting IBS-type symptoms since earlier this year confused by the issue that I've also got endometriosis in the intestinal area (found when my appendix was removed) and I've been starting to think I may have something going on with gluten and/or wheat, especially since I've had autoimmune problems all my life (JRA & lupus) and have just been diagnosed with Sjogrens Syndrome back in August to add to my collection - I'm now 46.

I kept eating my normal wheaty diet right up to the day of my blood test to make sure that the blood test worked correctly. However, when I was given my results this morning I was told that I had a false negative is usually seen in people who had excluded gluten from their diet. I started a gluten-free diet the day after my blood test to see if I noticed any changes and I have immediately noticed much less bloating and (sorry folks!) now I have 'normal poo' rather than diarrhoea. I have still had tummy aches and pains but I have been so anxious that there was something seriously wrong with me that I wonder if that has contributed to that problem.

The doctors have said that it's 'probably IBS' but of course I have worried myself sick that I had something gravely wrong with me since I couldn't get myself better. I'd really appreciate any thoughts that people on here might have about this so I can go into my doctor's appointment next Friday morning 'fully armed'!

5 Replies

Hi Lucy, A false negative usually occurs if you have just started to have coeliac disease; if you have the coeliac disease but very mildly; if you have been on a gluten free diet before the blood test is taken. It is recommended that a person who is going to have the blood test eats gluten every day for approximately eight weeks to ensure a correct reading.

There are a few people with coeliac disease who do not produce any antigens in their blood and so a blood test will never prove that they have the disease.

It is a very difficult thing in many to actually have a confirmed diagnosis for coeliac disease without having a biopsy and that is a personal choice that has to be made by the individual.

It also has been known for quite some time that there are many people with gluten intolerance that have identical symptoms to those of coeliac disease. I have gathered a few pieces of information together with varying recommendations so that you can see a fairly wide picture of current thinking.

There are many people who become sensitive to gluten or develop gluten allergy or coeliac disease when they are adults and something you will notice is that once you have taken gluten out of your diet it will make you more sensitive to digesting even small particles of it. Anyway, I hope the following pieces of information help you - if you are still not certain or have other things that you'd like to ask then please ask away - there is bound to be someone here who probably has similar circumstances and conditions to your own and will be able to give further advice.

The NHS site has the following information:

The US sites offer this information:

Probability of False Negative tests:


Ok Lucy here's the proof points you need to arm yourself with:

Did your GP test you for both of these?

- endomysial antibodies (EMA) and tissue transglutaminase antibodies (tTGA) ?

- these are known as 2 of the best coeliac blood tests just one often won't give a true picture


"Some research shows that patients with coeliac disease are more likely to be IgA deficient than the general population (2). People with IgA deficiency will have a false negative result if IgA-based serological tests are used in the diagnosis of coeliac disease."

So ask your Dr for the IgG test as well (but remember you'll have to be eating gluten):

"The NICE guideline recommends using IgG antibody blood tests in those who are IgA deficient."

My gyny Dr has said that there is new research that is emerging and believes that Endometriosis is actually an auto-immune disease. So it maybe that with your other problems it has flared up. I know as soon as I went GF I hit Endom hell. Some researchers in America believe this is often because whilst we're busy fighting gluten we are pumped full of cortisol and adrenalin and when we suddenly remove gluten the body tries to rebalance and any other inflammation can rise to the forefront. A right pain!

You'll probably know that Endometriosis UK recently publicised some research linking Colitis and Chrons with Endometriosis so it's worth asking yr Dr about being tested for those.



Of course there's a great Endometriosis group here on HealthUnlocked so do ask them for tips too.

Hope that helps.

Let us know if you need more ammo ; )


I found this information interesting as recently I have been diagnosed with palindromic rheumatism. I am coeliac but am careful to avoid gluten at all times. I started to get pain in various joints over a year ago which would cause intense debilitating pain in the joint but would suddenly improve usually within 24 hours. I also had stiffness in my feet and occassionally hands. I had some hand stiffness prior to being diagnosed as coeliac some 5 years ago so wondered if i was being unknowingly glutenised. I decided to get some bloods done for rheumatoid athritis. My test came back as positive but so low my doctor said it was a false positive as i had no clinical features of ra. Ie hot swollen joints. I asked to be referred to a rheumatologist and he diagnosed Palindromic rheumatism. Which basically means the joint is the same after the attack as before so it is quite difficult to diagnose as in between there are no symptoms. It is an auto immune disease so i now have three with my underactive thyroid, it can go on to develop into ra. So it ties in with the theory that my coeliac was suppressing the disease.


I too have a history of endometriosis, mine amongst other things perforating the bowel. I have scleroderma and raynauds too , both classed as auto-immune disorders and I have never managed to test positive for coeliac although both my specialists recommend a gluten free diet. Over the years I have found that I am very intolerant to wheat, and have to avoid it at all costs. I dont get precriptions but I found the coeliac community very supportive and knowledgable (much more so than my GP) and I understand them as the symptons I get when I have been "wheati-ified" as my husband calls it are just the same. if not worse than some people who have tested postive.

so I look after myself, avoid wheat (and carry toilet roll for those bad days)

Keep smiling you are not alone


Thank you so much for giving me such a wealth of information! I have found that in recent years there is not much help or support through the NHS for these kind of chronic health problems. It's taken me about 2 years to get the GP surgery to refer me back to a rheumatologist (despite having juvenile arthritis with liver & kidney failure at 16 and then being diagnosed with lupus about 10 years ago) - I knew that I probably had Sjogrens Syndrome from both symptoms and antibody status but the GP refused to take me seriously. All they want to do is shove you out of the surgery door with a prescription for some kind of medication.

I'm not sure whether they will tell me the details of which tests they performed for the coeliac test - I know that they took quite a few phials of blood and that they went to Southampton (I'm in Swindon). I find the medical services around here incredibly frustrating and am already on my 2nd GP surgery since moving to the area 5 years ago - from what I hear from other people, they are all very large and very similar in operational style unfortunately.

It seems as though I may have to reintroduce gluten at some point if I need to undergo further testing. I have never cut it out of my diet before and so I was interested to see if it made a difference. Is it normal to continue to have tummy aches and pains on a gluten-free diet? I have been gluten-free for two weeks now and the diahhroea and bloating has gone but I still feel pretty unwell in the abdominal area.

I am convinced that there is some issue with a food intolerance of some kind going on. I have had IBS-type symptoms in the past but they've never lasted this long before and with everything seeming to be flaring at the moment, I wonder if there is a connection. I have particularly been suffering with throat problems with problems swallowing effectively and having a weak, hoarse voice. Unfortunately I'm not due to see the rheumatologist again until next year for the Sjogrens - the consultant I saw does mention a link between the syndrome and gastro-intestinal problems: but she does not mention a problem with a gluten allergy or intolerance.


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