People With IBS Are Up to 3x More Likely to Develop Autoimmune Disease

If you have irritable bowel syndrome (IBS, a disorder marked by recurring abdominal pain and altered bowel habits without any visible structural damage), you have probably had the frustrating experience of doctors treating your symptoms as unconnected to anything else going on in your body. A new study of nearly half a million patients suggests that assumption may be wrong. Researchers found that people with IBS go on to develop autoimmune and inflammatory joint diseases, from lupus to rheumatoid arthritis, at meaningfully higher rates than people without IBS, adding weight to the idea that gut health and systemic immune function are more tightly linked than commonly assumed.

Key takeaways

• People with IBS had a 2 to 3 times higher risk of developing ankylosing spondylitis, psoriatic arthritis, Sjogren syndrome, and systemic sclerosis compared to matched non-IBS patients, and modestly higher risk of rheumatoid arthritis, gout, lupus, and dermatomyositis.
• The pattern held up across 459,966 propensity-matched patients from a global health record network and survived more than a dozen sensitivity checks.
• Researchers point to gut microbiome disruption and a leaky gut barrier as plausible biological links, but this study cannot prove IBS causes these diseases.
• The finding is a reason for awareness, not alarm: absolute risk for most of these conditions remained under 1%.

IBS Linked to Higher Risk of Autoimmune and Rheumatic Disease

People diagnosed with irritable bowel syndrome face a significantly elevated risk of later developing systemic rheumatic diseases, a category that includes both inflammatory arthritis (joint diseases driven by immune overactivity) and connective tissue disorders like lupus, according to a large cohort study published in Frontiers in Immunology. Among the strongest associations, IBS patients were roughly 2.6 times more likely to develop ankylosing spondylitis (a form of inflammatory arthritis that primarily affects the spine) and nearly 2.8 times more likely to develop Sjogren syndrome (an autoimmune condition that attacks the glands that produce tears and saliva), compared with matched people who never had IBS.

Why This Matters for the Roughly 1 in 10 People Living With IBS

IBS affects an estimated 10% of people worldwide, with women affected disproportionately, and it is already linked to reduced quality of life and missed work. This study adds a new dimension for that same population: increased downstream risk of ankylosing spondylitis, psoriatic arthritis, rheumatoid arthritis, gout, lupus, Sjogren syndrome, systemic sclerosis, and dermatomyositis. For anyone managing chronic IBS symptoms, particularly those with a family history of autoimmune disease, the takeaway is not that IBS causes these conditions, but that the two may share underlying biology worth understanding, and that new joint pain, dry eyes, or skin changes in someone with IBS are not necessarily "just IBS."

How Researchers Tracked Nearly Half a Million Patients

The researchers used the TriNetX Global Collaborative Network, a research platform that pools anonymized electronic health records from more than 150 healthcare organizations and over 150 million patients worldwide. They identified adults diagnosed with IBS (based on at least two clinical visits) between 2015 and 2023, then matched each of the 459,966 IBS patients 1:1 to a control patient without IBS, balancing the two groups for age, sex, race, weight, and major comorbidities like diabetes and hypertension using propensity score matching (a statistical technique that pairs patients with similar baseline characteristics so the groups differ mainly in whether they have IBS). People with pre-existing rheumatic disease, cancer, or inflammatory bowel disease were excluded from both groups.

Over follow-up, IBS patients showed higher rates of ankylosing spondylitis (hazard ratio 2.57), psoriatic arthritis (hazard ratio 2.03), Sjogren syndrome (hazard ratio 2.84), systemic sclerosis (hazard ratio 2.09), lupus (hazard ratio 1.84), dermatomyositis (hazard ratio 1.52), rheumatoid arthritis (hazard ratio 1.42), and gout (hazard ratio 1.34). A hazard ratio above 1 means the IBS group developed the condition at a higher rate over time than the control group. The associations held up when the researchers used stricter definitions of IBS, extended the waiting period between IBS diagnosis and the start of outcome tracking to 24 and 36 months, swapped in different comparison groups such as hernia or gastritis patients, and re-ran the analysis on a separate US-only version of the same database.

What This Could Mean If You Have IBS

This study does not mean everyone with IBS will develop an autoimmune disease, and the researchers were explicit that these results support awareness rather than routine screening. The absolute numbers stayed small even where the relative risk jumped the most: for example, 1,702 of 459,966 IBS patients developed Sjogren syndrome, compared with 638 in the matched control group. Still, the authors suggest that new, persistent joint pain, unexplained dryness of the eyes or mouth, or skin changes in someone with a long-standing IBS diagnosis could be worth mentioning to a doctor, since delayed recognition of rheumatic disease can affect long-term outcomes. The study does not establish that any diet, supplement, or probiotic changes this risk, and no such intervention should be assumed to work based on these findings.

Why the Study Cannot Prove IBS Causes These Diseases

The researchers are upfront that this is an association, not proof of cause and effect. The database relied on diagnostic codes entered during routine care rather than confirmed clinical criteria, so some misclassification of IBS or the rheumatic outcomes is possible. People with IBS also generally see doctors more often, which could mean some of these autoimmune conditions were simply caught sooner or more frequently in this group, a problem known as surveillance bias. There is also the possibility of reverse causation: some rheumatic diseases, especially Sjogren syndrome and systemic sclerosis, can produce vague symptoms for years before diagnosis, so a slow-developing autoimmune disease could in theory be mistaken for IBS in its early stages, rather than IBS causing the disease. The study did not include any blood tests, stool samples, or other biological measurements, so it cannot directly confirm the gut microbiome mechanisms it proposes.

The Gut-Immune Mechanism Behind the Link, and What Comes Next

The study's authors point to a plausible biological explanation rather than a confirmed one. IBS has increasingly been linked to low-grade inflammation in the gut lining, increased intestinal permeability (sometimes called "leaky gut," where the intestinal barrier lets more bacterial byproducts and immune triggers pass into the bloodstream), and shifts in the balance of gut bacteria species that make up the microbiome. Separately, gut microbiome disruption has already been documented in several of the autoimmune conditions in this study, including Sjogren syndrome and rheumatoid arthritis, giving the authors a plausible, though unproven, shared pathway: a disrupted gut barrier and altered microbiome triggering the kind of immune system overactivation seen in autoimmune disease. The researchers call for further studies that combine clinical tracking with actual microbiome and immune-marker testing to determine whether this biological link is real and, if so, whether treating gut health earlier could reduce downstream autoimmune risk.

Common Questions

Does IBS cause autoimmune disease? No. This study only shows a statistical association between an IBS diagnosis and a higher rate of later autoimmune and rheumatic disease diagnoses; it cannot prove that IBS causes those conditions.

Which autoimmune conditions were most strongly linked to IBS in this study? Sjogren syndrome (hazard ratio 2.84) and ankylosing spondylitis (hazard ratio 2.57) showed the strongest associations, followed by systemic sclerosis (hazard ratio 2.09) and psoriatic arthritis (hazard ratio 2.03).

Should people with IBS get tested for autoimmune disease? The study authors say these findings support general awareness, not routine screening for all IBS patients. Anyone with IBS who develops new joint pain, dry eyes or mouth, or unexplained skin changes should mention it to a doctor.

Does treating IBS reduce the risk of these diseases? This study did not test that question, and no diet, supplement, or IBS treatment has been shown to lower autoimmune disease risk based on this data.

References

1. Shuo-Yan Gau, Yu-Jung Su, Shih-Chi Yang, et al. (2026). Risk of systemic rheumatic diseases in people with irritable bowel syndrome: a global-federated cohort analysis. Frontiers in Immunology. https://doi.org/10.3389/fimmu.2026.1779191
2. Xuemei Li, Qiang Yuan, Hui Huang, Li Wang (2025). Gut microbiota in irritable bowel syndrome: a narrative review of mechanisms and microbiome-based therapies. Frontiers in Immunology. https://doi.org/10.3389/fimmu.2025.1695321
3. Roberto Mendez, Arjun Watane, Monika Farhangi, et al. (2020). Gut microbial dysbiosis in individuals with Sjögren’s syndrome. Microbial Cell Factories. https://doi.org/10.1186/s12934-020-01348-7