Can Gut Problems Cause Fatigue, Joint Pain, Anxiety or Hair Loss?

Written by AT. Chintan Dalal, N.D. · Reviewed by Dr Krushal Pabari, Clinical Team, Cure4Pain · Updated 30 October 2026

Key facts

Gut problems can cause fatigue and joint pain in specific conditions that can be tested for, while the evidence is weaker for anxiety and hair loss. Fatigue affects about 47% of adults with inflammatory bowel disease, according to a 2022 analysis of 20 studies [1], and the UK’s NHS advises a coeliac test for prolonged tiredness [2]. Arthritis affects about 13% of people with inflammatory bowel disease, according to a 2017 analysis of 71 studies [3], and about 2.6% of people develop reactive arthritis after certain bacterial gut infections, according to a 2021 analysis of 24 articles [4]. Anxiety and functional gut disorders can each come first, according to a 2016 population study in Australia [5]. For hair loss linked to gut problems, the best-supported routes are indirect: low iron, weight loss or illness [6] [7]. Gut bacteria differ in people with joint disease and with anxiety, but these studies show a link, not a cause [8] [9].

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Can gut problems cause symptoms outside the gut?

Yes. Gut problems can cause symptoms outside the gut in some conditions, including inflammatory bowel disease and coeliac disease, through poor absorption or blood loss, immune inflammation or gut-brain signalling. The American College of Gastroenterology describes coeliac disease in its 2023 guideline as resembling “a multisystemic disorder rather than an isolated intestinal disease” [10], and the NHS advises a coeliac test for prolonged tiredness [2].

Three routes are described:

• Poor absorption or blood loss: gut disease such as coeliac disease can lower iron, vitamin B12 and folate [11] [12]. The British Society of Gastroenterology (BSG) 2021 guideline names malabsorption and gut disease among the causes of iron deficiency anaemia [13].
• Immune inflammation: arthritis and other rheumatic features are recognised in inflammatory bowel disease, and coeliac disease can resemble a multisystemic disorder [3] [10].
• Gut-brain signalling: the BSG now classes IBS as a disorder of gut-brain interaction [14], which fits the two-way link between IBS and anxiety.

Less settled is the popular idea that “poor gut health” or leaky gut explains all of these symptoms. It is still unproven that restoring the gut barrier improves disease inside or outside the gut, according to a 2019 review in the journal Gut [15]; see our article on leaky gut tests. Our gut dysbiosis page covers gut balance and its care, and psoriasis and gut health covers the skin.

Can gut problems cause fatigue?

Gut problems can cause fatigue in some conditions. Fatigue is common and well documented in inflammatory bowel disease, coeliac disease and IBS, though the reason differs by condition, and in IBS the evidence shows a link rather than a proven cause. The NHS lists feeling tired all the time among the main symptoms of inflammatory bowel disease [16].

Gut condition	What studies found	Cause or link?
Inflammatory bowel disease	Fatigue in 47% across 20 studies: 72% with active disease and 47% with controlled disease [1]	Worse when disease is active; anaemia, poor sleep, anxiety and depression also contribute [1] [17]
Coeliac disease	In a 2023 controlled study of 78 people with coeliac disease, median fatigue scores fell by about half or more after 12 months gluten-free, yet stayed above those of healthy people [18]	Likely a cause. It may reflect anaemia [11]; in this study, fatigue tracked depression and pain rather than nutrient deficiency [18]
IBS	Fatigue in about 54% in two analyses [19] [17]	A link: it goes with gut symptoms and psychological distress [19]
H. pylori infection	Iron deficiency more likely (odds ratio 1.33, 30 studies) [20]	Indirect, through iron; these studies measured iron, not fatigue
ME/CFS (chronic fatigue syndrome)	IBS in 37% of people with ME/CFS [21]; 7 studies of gut bacteria gave inconsistent results [22]	A link: evidence is insufficient that gut bacteria play a significant role [22]

Does treating the gut problem or the deficiency help the fatigue? The evidence is mixed:

• Iron: in a 2018 review of 18 trials in iron-deficient adults without anaemia, iron reduced self-reported fatigue (4 trials, 714 people) but did not improve measured physical capacity [23]. See iron deficiency without anaemia.
• Vitamin B12: in a 2018 randomised trial of 95 people with IBS or inflammatory bowel disease, fatigue and normal B12 levels, 8 weeks of B12 did no better than placebo on the main fatigue score [24]. Testing comes first; see vitamin B12 deficiency.
• Gut bacteria: in a 2020 placebo-controlled faecal transplant trial, 83 people with moderate to severe non-constipated IBS were analysed, and more had a fatigue response at 6 months on active treatment (odds ratio 4.4) [25]. This was a secondary outcome of one small trial.

Constant tiredness also has common causes outside the gut, such as poor sleep, stress, depression, hormonal change and some medicines, according to the NHS [26]. Our article on why you may always feel tired covers them.

Can gut problems cause joint pain?

Gut problems can cause joint pain in inflammatory bowel disease and after certain gut infections, where arthritis is a recognised complication. For IBS and for gut bacteria in general, the evidence shows an overlap rather than a cause.

Gut problem	What studies found	Cause or link?
Inflammatory bowel disease	Arthritis in 13%, sacroiliitis (inflamed joints at the base of the spine) in 10% and ankylosing spondylitis in 3%, across 71 studies [3]	A recognised rheumatic feature of the disease
Gut infection	Reactive arthritis in about 2.6% after Campylobacter, Salmonella, Shigella or Yersinia, with wide variation between studies [4]. It usually starts 1 to 4 weeks after an infection and usually goes within 6 months, though it can last longer [27]	Direct: it follows the infection
Coeliac disease	Joint complaints in 10.7% of 6,901 people with no rheumatic diagnosis, across 27 studies [28]	A link: the analysis measured how common it is
IBS and fibromyalgia	Aching joints in 62.4% with mixed-type IBS, among 4,862 people with IBS [29]; IBS is common in fibromyalgia, across 14 studies [30]	Overlap: the IBS study had no comparison group
Gut bacteria	Lower diversity in rheumatoid arthritis, lupus, gout and fibromyalgia, across 92 observational studies with 11,998 people; little specificity to one disease [8]	A link: observational studies cannot show which came first

Joint disease can also come with gut inflammation: in a 2013 Belgian study of 65 people with spondyloarthritis, 46.2% had microscopic gut inflammation on colonoscopy [31]. Trials of gut-targeted treatments for joint disease are so far less encouraging than the theory. A 2024 analysis of 80 trials found that gut microbiota-based treatments may not improve spondyloarthritis or rheumatoid arthritis, and may ease fibromyalgia pain without changing the overall impact score [32]; a 2010 randomised trial of a probiotic in 63 people with active spondyloarthritis found no benefit over placebo [33].

Joint pain has many causes outside the gut, including injury, osteoarthritis, rheumatoid arthritis, gout and the menopause, according to the NHS [34]. See also deficiencies linked to joint and muscle pain and CRP, ESR and ANA results.

Can gut problems cause anxiety?

IBS and functional dyspepsia can come before anxiety, and anxiety can come before them, so the link runs in both directions, according to a 2016 Australian population study [5]. Which comes first differs from person to person, and it is not proven that gut bacteria cause anxiety disorders [9].

• How common: a 2019 analysis of 73 papers found anxiety symptoms in 39.1% and anxiety disorders in 23% of people with IBS, with about 3 times the odds of anxiety symptoms compared with healthy people [35]. In inflammatory bowel disease, 32.1% had anxiety symptoms across 58 studies, 57.6% with active disease against 38.1% with inactive disease [36].
• Which comes first: in a 2016 Australian population study of 1,900 people followed for a year, the authors calculated that a mood disorder came first in one third and IBS or functional dyspepsia in two thirds [5]. People with anxiety at the start had about double the risk of later IBS in a 2016 analysis of 11 studies, 8 of them in people with a gut infection (relative risk 2.38), with less support when anxiety was diagnosed by clinical interview [37]. The risk of anxiety was also about 1.5 times higher after a diagnosis of inflammatory bowel disease in a 2023 analysis of cohort studies (hazard ratio 1.48) [38].
• Anxiety itself causes gut symptoms: the NHS lists indigestion, stomach cramps, bloating, nausea, constipation and diarrhoea among the physical symptoms of anxiety [39].
• Gut bacteria: only 3 of 26 studies in a 2021 review looked at diagnosed anxiety disorders; findings on gut bacterial diversity were inconsistent, and the authors say diet and medicines need better control [9].
• Probiotics: in a 2025 review of 72 trials, 49 measured anxiety, and probiotics, prebiotics and synbiotics lowered anxiety scores more than placebo, but quality was limited and results varied widely [40]. A 2023 analysis of 29 trials disagreed on prebiotics, which did not beat placebo; it found a small effect for probiotics and synbiotics and called it premature to conclude clinical efficacy [41].

The NHS lists talking therapies, usually cognitive behavioural therapy, and medicines as the main treatments for generalised anxiety disorder [42]; gut treatment does not replace them. Anxiety can also come from an overactive thyroid, which causes nervousness, irritability and tiredness, according to the NHS [26].

Can gut problems cause hair loss?

Gut problems can contribute to hair loss, and the best-supported routes are indirect: low iron, weight loss or the strain of illness, which the NHS lists among the causes of temporary hair loss [6]. Direct evidence that a gut condition or gut bacteria cause hair loss is thin, and we found no randomised trial of a gut treatment for alopecia areata, the patchy autoimmune form, in a PubMed search in October 2026.

Route	What studies found	Cause or link?
Low iron	Women with non-scarring hair loss had lower ferritin across 36 studies [43]; iron deficiency anaemia is common in coeliac disease at diagnosis [12]	Indirect and likely; hair loss is a less common symptom of this anaemia [44]
Sudden weight loss	A recognised trigger of temporary shedding (telogen effluvium) [45]	Indirect, through the weight loss
Inflammatory bowel disease	Flares are probably the commonest disease-related cause of hair loss, according to a 2013 literature review; other causes include medicine side effects and deficiencies; how often it happens is unknown [7]	Plausible, with little data
Coeliac disease and alopecia areata	In a 1995 report, coeliac disease was found in 3 of 256 people with alopecia areata who were screened, none with gut symptoms [46]. Hair regrew in one boy on a gluten-free diet in that report, but not in 5 people in a 2000 case series [47]	A link, from small studies
IBS and alopecia areata	Studies disagree: about 5 times the risk in both directions in a 2022 nationwide cohort study in Taiwan [48], yet lower odds (0.38) in a 2023 analysis of 102 studies [49]	Unclear
Gut bacteria	The bacterial mix differed in 19 people with alopecia areata against 20 controls [50]	Early and unconfirmed

Which other causes of fatigue and hair loss are worth testing?

Fatigue and hair loss often have causes that have nothing to do with the gut. The NHS lists tiredness and hair loss among the symptoms of both an underactive thyroid and iron deficiency anaemia, where hair loss is less common [51] [44], and several causes can be found with a blood test or a careful history.

Poor sleep, stress, depression and hormonal change are common causes of tiredness [26], and pattern hair loss, which is typically genetic, is the most common form of hair loss [52]. Blood tests do not always explain hair shedding: in a 2024 case-control study of 90 women with chronic shedding and 90 controls, zinc was lower, while haemoglobin, ferritin, vitamin B12, thyroid tests, vitamin D and biotin did not differ [53]. Our article on blood tests for chronic pain and fatigue lists what to ask for.

Which gut tests are worth doing for these symptoms?

The most useful gut tests for fatigue, joint pain, anxiety or hair loss look for a named condition, such as coeliac antibodies and faecal calprotectin, because the result changes what happens next.

• Coeliac antibodies: the NHS advises testing for prolonged tiredness, unexplained iron, B12 or folate deficiency anaemia, IBS in adults or autoimmune thyroid disease. Keep eating gluten until the test is done, because avoiding it can make the result inaccurate [2]. In a 2018 analysis of 18 studies, about 1 in 31 people with iron deficiency anaemia had biopsy-confirmed coeliac disease [54]. If it is confirmed, the American College of Gastroenterology’s 2023 guideline sets out a strict gluten-free diet and lifelong medical follow-up [10].
• Faecal calprotectin: a stool test that NICE (the UK’s health guideline body) recommends to help tell inflammatory bowel disease from IBS in adults with recent lower gut symptoms when cancer is not suspected [55].
• Search for the cause of low iron: about a third of men and postmenopausal women with iron deficiency anaemia have an underlying abnormality, most often in the gut, according to the BSG [13].

Commercial microbiome tests are discussed on our gut dysbiosis page.

When should you see a doctor?

See a doctor soon if tiredness or joint pain is lasting and unexplained. The NHS also lists bowel warning signs that need review, including blood in your stool, weight loss without trying and a change in bowel habit [56] [57].

• Bowel warning signs: a change in bowel habit that is not usual for you, blood in your stool, weight loss without trying, a lump in your tummy, or feeling very tired or short of breath [56] [57]. Diarrhoea lasting more than 7 days also needs review [16].
• Get urgent help: black or dark red stools, bloody diarrhoea, severe tummy pain, heavy bleeding from your bottom, or vomiting blood [56] [16]. Call your local emergency number or go to the nearest emergency department if the pain or bleeding is severe.
• Joints: a hot, swollen joint or joint pain with a high temperature needs urgent review; stiffness lasting more than 30 minutes after waking needs a routine appointment [34].
• Tiredness: tired for a few weeks without knowing why, or tiredness with weight loss or mood changes [26].
• Mood: anxiety that affects daily life needs a medical review [42]. Thoughts of harming yourself need urgent help: call your local emergency number or go to the nearest emergency department [58].
• Hair: see a doctor if you are worried about your hair loss, and before going to a commercial hair clinic [6].

How we assess these symptoms at Cure4Pain

At Cure4Pain we start with tests, because the same symptom can have a gut cause or a non-gut cause.

• Tests first: we read a panel of about 100 markers, adding tests for your condition when clinically indicated. When gut symptoms are part of the picture, these are stool tests for inflammation and parasites, a SIBO breath test, an H. pylori test and coeliac antibodies, done before wheat is replaced, in line with the NICE and NHS advice above [55] [2].
• Diet, when gut care is part of your plan: milk and most dairy, sugar, processed foods, nightshades and raw foods are removed, with home-set curd where it suits you, ghee allowed and whole raw fruit once in a while. We generally advise most patients to replace wheat with jowar, bajra or other millets as a general health measure; research supports a gluten-free diet for coeliac disease confirmed by testing [10]. As an observational clinic practice, we generally suggest limiting cruciferous (Brassica) vegetables such as cabbage and cauliflower, although a 2024 review found that normal intake with enough iodine does not harm thyroid function [59]. We found no trial of this diet combination for fatigue, joint pain, anxiety or hair loss.
• Gut support: Saccharomyces boulardii and other probiotics, digestive enzymes, bile support, glutamine, zinc, thiamine and magnesium, as explained on our gut dysbiosis page, with supervised gut protocols managed by Dr Krushal Pabari for small intestinal bacterial overgrowth (SIBO). Given by mouth first, with injections only when specifically needed or advised; magnesium mainly as bisglycinate, with L-threonate or citrate as advised, counted as elemental.
• Vitamin D: supervised-dose vitamin D therapy (Coimbra Protocol-based methods), mainly for people with an autoimmune condition or low vitamin D; see our Coimbra Protocol page. Our methods are derived from the work of Dr Coimbra. We found no trial of the Coimbra Protocol for fatigue, joint pain, anxiety or hair loss.
• Stress and anxiety: breathing, relaxation, restorative sleep and counselling, with referral to the psychiatrist who works with our team when needed.
• Medicines: at Cure4Pain, Dr Krushal Pabari prescribes and adjusts medicines for inflammatory bowel disease as per guidelines, under clinical guidance from Team Cure4Pain, in coordination with your existing consulting physician and gastroenterologist; he recommends IV iron or biologics where needed, or redirects you to the right expert. Acid-reducing medicines, antibiotics and painkillers are reviewed case by case; never stop or change them on your own.
• Further tests and referral: Dr Krushal Pabari recommends endoscopy or colonoscopy where the diagnosis calls for it. We refer you to a gastroenterologist when an ulcer, cancer or other serious cause is suspected, and for symptoms at night, a family history of bowel cancer, or new bowel symptoms after the age of 50 to 60.

This is our clinic practice; individual results vary, and further studies are needed.

If you would like these symptoms assessed together, you can book a consultation, online from anywhere or at our Mumbai clinic.

Frequently asked questions

What gut problems cause fatigue?

Fatigue is best documented in inflammatory bowel disease (about 47% of adults, in a 2022 analysis of 20 studies), coeliac disease and IBS (about 54%, in a 2024 analysis). Low iron, including from H. pylori infection, can add to it, so tiredness that does not settle deserves testing. [1] [18] [17] [20]

Can IBS cause fatigue and joint pain?

Fatigue and joint pain are both reported often in IBS: fatigue in about 54% of people with IBS in a 2024 analysis, and aching joints in 62.4% with mixed-type IBS in one 2024 study without a comparison group. A swollen or hot joint needs urgent review, according to the NHS. [17] [29] [34]

Can leaky gut cause joint pain?

Leaky gut has not been shown to cause joint pain. Raised gut permeability is found in some inflammatory diseases of the bowel, but a 2019 review in the journal Gut says it is still unproven that restoring the barrier improves symptoms inside or outside the gut. [15]

Can poor gut health cause anxiety?

IBS and functional dyspepsia can come before anxiety, and anxiety can come before them, according to a 2016 Australian population study. It is not proven that gut bacteria cause anxiety disorders, and a 2021 review says diet and medicines need better control in these studies. [5] [9]

Do probiotics help anxiety?

Pooled trials of probiotics, prebiotics and synbiotics show lower anxiety scores than placebo in a 2025 analysis of 72 trials, but a 2023 analysis of 29 trials found the effect small. Study quality is limited, and no best strain or dose is agreed. Probiotics do not replace talking therapy or prescribed medicine. [40] [41] [42]

Can IBS cause hair loss?

IBS has not been established as a cause of hair loss. A 2022 Taiwanese cohort study linked IBS with alopecia areata, while a 2023 analysis of 102 studies found lower odds, and neither shows cause. Tests for iron and thyroid function are more useful. [48] [49] [44] [51]

Can H. pylori cause hair loss?

H. pylori has not been established as a cause of hair loss. A 2017 case-control study in Iran of 81 people with alopecia areata and 81 controls found H. pylori in 53.1% against 33.3%, which is a link only. H. pylori is also linked with iron deficiency, and hair loss is a less common symptom of iron deficiency anaemia, according to the NHS. [60] [20] [44]

Can SIBO cause hair loss?

Our PubMed search in October 2026 found no study of small intestinal bacterial overgrowth (SIBO) as a cause of hair loss. If you have both, it is reasonable to check iron and thyroid function and to assess each problem separately. [44] [51]

Will hair grow back if the gut problem is treated?

Hair loss caused by a medical condition usually stops or grows back after recovery, according to the NHS. Results for gut treatments are limited: a gluten-free diet did not bring regrowth in 5 people with coeliac disease and alopecia areata in a 2000 case series. [6] [47]

Should I stop gluten to see if my symptoms improve?

Do not stop gluten before testing for coeliac disease. The NHS advises eating gluten until the coeliac test is done, because avoiding it can make the result inaccurate. [2]

This article is for education and does not replace medical advice. Do not start, stop or change any medicine or supplement without medical guidance.

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