Nearly 80% of women in Australia suffer from thyroid-related problems.
But only 40% of Australian women TSH levels meet the blood levels to diagnose hypothyroid, hyperthyroid, parathyroidism, hyper parathyroidism, Hashimoto’s or Graves disease.
Many women suffer with subclinical hypothyroidism, or suboptimal Hashimoto’s because their blood work is “normal”. And they are left to assume their symptoms are depression, hormones, or because of their unhealthy lifestyle and diet choices.
Changing hormones, during peri/post menopause, trigger both the Thyroid-Gut Axis AND the Thyroid-Adrenal Axis (HPA Axis). This can cause confusion as to whether symptoms are thyroid, gut, and/or menopause related.
Today, I wanted to give you a potential tool, that can help you ask different questions to hopefully better understand a diagnosis OR assist in one digestive symptoms commonly associated with thyroid conditions.
Digestive discomfort and thyroid issues often go hand in hand more than people realise.
For many women, especially those with autoimmune thyroid conditions like Hashimoto’s or Graves’ disease, gastrointestinal symptoms such as those seen in irritable bowel syndrome (IBS) appear years, sometimes 5 to 15 years, before a thyroid diagnosis.
This isn’t a coincidence.
The gut and thyroid influence each other in powerful ways, creating a cycle where one imbalance can worsen or even trigger the other.
Understanding IBS and Healthy Gut Function
IBS involves symptoms like:
- recurring abdominal pain,
- bloating,
- excessive gas,
- changes in bowel habits (diarrhoea, constipation, or alternating between the two), and
- a feeling of incomplete evacuation.
Unlike structural diseases, IBS doesn’t show obvious damage on standard tests. It is diagnosed based on symptom patterns, often using criteria like recurrent pain for at least three months, combined with alterations in stool frequency or form.
In contrast, healthy digestion feels effortless:
- regular bowel movements (typically 1–3 times daily or every other day),
- soft and well-formed stools,
- minimal bloating or discomfort after eating, and
- the ability to tolerate a wide range of foods without issues.
Many people receive an IBS label after months or years of unexplained symptoms, only to find that conventional treatments focus mostly on symptom relief.
Things like antispasmodics, rather than digging deeper.
This approach often falls short long-term, leaving many still struggling.
How Thyroid Function Influences the Gut (and Vice Versa)
Thyroid hormones play a central role in regulating metabolism throughout the body, including the digestive system.
When thyroid levels are low (hypothyroidism or suboptimal function in Hashimoto’s), everything slows down:
- Reduced production of digestive enzymes and bile acids impairs the breakdown of food.
- Slower gut motility leads to constipation, a hallmark symptom in hypothyroidism.
- Altered gut environment promotes bacterial imbalances (dysbiosis), where harmful bacteria or yeast overgrow and beneficial ones decline.
On the flip side, gut problems can harm thyroid health.
Chronic diarrhoea (common in some IBS types) causes poor nutrient absorption, depleting key thyroid-supporting nutrients like selenium, zinc, iron, and B vitamins.
This can contribute to or worsen hypothyroidism.
Shared underlying factors amplify the connection:
- Intestinal permeability (“leaky gut”): Gaps in the gut lining allow undigested particles, toxins, and bacteria to enter the bloodstream, triggering immune responses that can fuel autoimmunity in genetically susceptible people.
- Small intestinal bacterial overgrowth (SIBO): Seen in a large percentage of hypothyroid cases and many with IBS, leading to bloating, malabsorption, and further nutrient deficiencies.
- Dysbiosis and infections: Imbalanced gut flora or lingering pathogens (from past infections) disrupt motility, increase inflammation, and promote permeability.
- Stress: Chronic stress alters gut motility, microbiota composition, and barrier function while also taxing the thyroid-adrenal axis.
- Hormonal influences: Women are disproportionately affected by both IBS and thyroid autoimmunity, with oestrogen fluctuations playing a role in gut sensitivity.
Studies show a notable portion of people with IBS have underlying thyroid dysfunction (often subclinical), while thyroid patients frequently report IBS-like symptoms.
Beyond the Label: Looking for Root Causes
Conventional medicine often treats IBS as a standalone condition, but many cases stem from identifiable triggers that, when addressed, lead to lasting improvement:
- Food sensitivities or intolerances.
- Enzyme or bile deficiencies hindering digestion.
- Nutrient shortfalls that impair gut repair and thyroid function.
- Gut infections or overgrowths (bacterial, yeast, or parasitic).
- Chronic low-grade inflammation or misdiagnosed conditions (e.g., celiac disease or early inflammatory bowel issues sometimes mistaken for IBS).
Testing for these factors and personalising nutrition, daily life, and stress or sleep hygiene, to just name a few, often yields better outcomes than symptom suppression alone.
If you’re dealing with weekly or persistent digestive issues alongside thyroid symptoms like:
- fatigue,
- brain fog,
- hair loss,
- mood changes,
- sleeping challenges,
- temperature sensitivity,
consider that they may share a connection.
Exploring the gut-thyroid axis through comprehensive evaluation can uncover overlooked connections and open the door to real recovery.
Many people find significant relief by prioritising gut health: supporting digestion, healing the gut lining, balancing the microbiome, and optimising thyroid function.
This shifts the focus from merely managing symptoms to resolving the underlying drivers for long-term lasting solutions, with easy everyday adjustments you can make.
The thyroid-gut axis and the thyroid-adrenal axis (HPA Axis) affect digestion.
And both are triggered during peri/post menopause.
Which is why so many symptoms can be “blamed” on hormones when our blood work is “normal”.
This is why we put together our webcast, Thyroid Gut Adrenal: A Deeper Look into Thyroid Function. You can register to watch the full webcast here: https://naturalhormonebalance.co/free-training-thyroid-gut-adrenal/
If you are ready to get support and would like to connect with us, please organise a Free Introductory Consultation with us here: https://calendly.com/nz-naturopathy/intro-consult
I hope you found this helpful.
We look forward to connecting with you again soon.
Warmly,
Tiaan
