Thyroid UK
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Low Thyroid output and IBS-d?

I wonder if anyone can shed any light on this.

I have suffered with IBS-d for years and recently had blood tests done to see if there was anything majorly wrong. The results came back clear all apart from borderline thyroid output. I assume by borderline that means low!

Has anyone else suffered, heard of or even have the same thing as I am really feeling quite low and ultimately a little worried about this.

9 Replies

IBS is a syndrome - so again it is something the Docs are not sure about.  So many suggestions about the cause and the treatment.  I have/had Crohns for over 40 years so have just a little experience with guts :-)

The thyroid produces hormones - mainly T4 and T3.  The T4 is a storage hormone and has to convert into the ACTIVE thyroid hormone T3.  The brain has the most receptors for T3 and the lining of the gut/immune system - has the second highest.  So in my non medical opinion - when the FT3 is LOW - then there is not enough T3 to go around EVERY cell of the body - and things begin to go wrong.

Also the food we eat is not the food we ate in days/years gone by.  Too many processed ingredients and of course gluten is an issue - even if you do not full blown celiac disease.  The wheat of today is not the wheat of old - sadly.

So what thyroid tests have you had done ?  Do post your results with ranges and people will comment.  Also you will have absorption issues so it would be good to have Ferritin - Folate - B12 - iron VitD tested.  ALL need to be OPTIMAL for your body to be healthy and for thyroid hormones to work efficiently in the body ....

Your are entitled to have copies of your test results by law - so always ask for them so you can monitor your own progress.

i am not a medic - just a thyroid sufferer with a B12 issue ....  :-)

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Wow that's a great reply, thank you!

I could not actually tell you the tests I have had done as the first one was just a general blood test to see if I had anything picked up that could be causing the IBS. These results were completely clear for Pancreas and Kidney function etc so I am ok on that front. It's just the thyroid output was put down to borderline!

I actually had a stool test done which came back 'borderline' too. That bloody word 'borderline' gets me though as I have no idea what I am borderline for!

I will see if I can get a copy of my results this time around and post them to see what people think.

So in effect would you say your thyroid issues came about with your Crohns? or vice versa?

I have literally today started a Wheat free diet in the hope that that could help me a little. I had lots of 'Free From' foods delivered to me last night so and keen to eat it and see how things go.

In the meantime I have to just sit and wait for the test results to come back. That really helps with anxiety doesn't it?!


...anxiety is something that can accompany low thyroid !  When you have your test results - post them in a new post in case they are missed in this thread !

Regarding the chicken and egg scenario with the Crohns - do click onto my name and have a read of my Profile - the shortened version !

What test results are you waiting on ?  These are the tests you need - TSH - FT4 - FT3 - Anti-TPO - Anti-Tg and the Vitamins and minerals I mentioned above.  Just for starters :-)

You could have Private Testing done through Thyroid UK - sent to your home ....

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My goodness this is going to open a can of worms isn't it?!

Again I do not know the tests that I am having done this time. He just said I need my bloods done again to check my thyroid output. When I speak with him regarding these I will ask for a print out and post them.

Just to give me some awareness of what I am looking for with these results when they come in, what should I be looking out for? I would ask what's normal, but, let's face it is anybody normal ;-)


The above link takes you to the main website of Thyroid UK. Everything you need to know and more :-) Ensures you are steps ahead of your Doc. Yours does sound quite good as you are being re-tested - now for the next step ....


"Normal" and "borderline" are both words that drive the people on this forum nuts. It never matters what is wrong with the patient. If everything is "normal" or "borderline" or "subclinical" according to the blood test results then all symptoms are in their head and they can be prescribed anti-depressants, and sometimes drugs for anxiety as well.

And then, if you get a copy of your results, you find that some of the tests that were "normal" weren't done at all, and borderline or subclinical results show up as being out of range or right at the bottom of the range or right at the top.

Regarding thyroid blood tests, the most commonly done test is TSH (thyroid stimulating hormone), which is actually produced by the pituitary not the thyroid. They do the others rarely (if at all) to save money.

A high TSH shows that thyroid output is low and the pituitary is trying to flog the thyroid to produce more hormone. This would be what you find in hypothyroidism (underactive thyroid). (In an ideal world. My explanation is hugely simplified.)

A low TSH shows that thyroid output is high and the pituitary reduces TSH down to nothing or almost nothing to reduce the output of the thyroid. This would be what you find in hyperthyroidism (overactive thyroid). (In an ideal world.)

I had all sorts of problems with alternating constipation and diarrhoea. It is difficult to say what helped - I've done so many things over the last few years to improve my health, including improving vitamins and minerals, and treating my own thyroid. If you think your gut is inflamed look into things like probiotics, prebiotics, kefir, fermented vegetables, L-Glutamine powder, zinc. You might have problems with (for example) gluten, casein, lactose.


These replies are great! Thank you so much. It's getting things clear in my head and working out what my body is playing at!!

Will see what the results come in at next week and post them on here for people to let me know what they think.

I do get anxiety quite a bit so worrying over everything doesn't help. Although they have never given me pills for this I wonder if this may be the next step they try with me.

I will be buying some probiotics at the weekend to start trying those as well as trying to cut out wheat and gluten. Fingers crossed for an improvement.

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Marz posted a very good link earlier today that may be relevant to you and is well worth reading :

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Thank you very much!! It's too long to read at work lol but I will be reading that tonight when the baby is finally in bed!!

I love this website and the forum, everyone is so friendly and helpful!!!


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