5 Questions About IBS and Axial Spondyloarthritis

More than half of all patients with ankylosing spondylitis (AS) report frequent gut pain and diarrhea. However, while microscopic gut inflammation is common in this disease, such inflammation has not been clearly linked to symptoms, and data are overall limited on the cause of gut pain/diarrhea in patients with axial spondyloarthritis (axSpA).

Johan K. Wallman, MD, PhD, from the Section of Rheumatology, Department of Clinical Sciences Lund, at Lund University in Sweden, and colleagues compared the prevalence of gut symptoms that met ROME III criteria for IBS between patients with axSpA and a control group.

Findings of the study indicated that gut symptoms that met IBS criteria were significantly more frequent among patients with axSpA (30%) than controls (16%).¹

Rheumatology Consultant caught up with Dr Wallman about the research.

RHEUM CON: What prompted you to conduct your study?

Johan Wallman: A well-known association exists between axSpA and inflammatory bowel disease (IBD); 5% to 10% of patients with axSpA have clinically apparent IBD.² Beyond that, up to 50% to 60% of patients with axSpA display microscopic gut inflammation at ileocolonoscopy,³ but neither such findings, nor elevated fecal calprotectin—which is also present in 40% to 75% of patients—have been clearly linked to gut symptoms.^3,4 Despite this, it has been reported that more than 50% of patients with axSpA have frequent gut symptoms,⁵ which thus prompted us to conduct this study in order to investigate another potential cause.

RHEUM CON: What are the most important findings from your study for rheumatologists to know about?

JW: In our well-characterized SPARTAKUS cohort of axSpA, the frequency of IBS symptoms was twice as high among patients with axSpA compared with controls. Furthermore, no clear associations were observed between the presence of such IBS symptoms and levels of fecal calprotectin or C-reactive protein levels, making gut inflammation unlikely as a main cause behind these symptoms. Although, it is important to acknowledge that no endoscopic examinations were performed as part of this study. Side effects of nonsteroidal anti-inflammatory drugs were also investigated as a potential cause of the observed symptoms, but the factors found to be most closely related to the presence of IBS symptoms were female sex (also overrepresented among patients with clinical IBS in the general population) and comorbid fibromyalgia (known to be closely associated with clinical IBS in the general population). Based on this, we hypothesized that clinical IBS may be a previously overlooked, frequent comorbidity in axSpA.

RHEUM CON: What are the current challenges that rheumatologists face when treating a patient with axSpA and IBS?

JW: Since the relationship between axSpA and IBS remains sparsely investigated to date, one of the most important challenges at this stage is confirming the overrepresentation of IBS in patients with axSpA by conducting further studies that also include endoscopic examinations. Another important challenge is increasing the awareness of this potential relationship among rheumatologists, as well as gastroenterologists, in order to be able to provide adequate symptom-relieving therapy to these patients.

RHEUM CON: How important is a multidisciplinary approach to management among this patient population, and when should a gastroenterologist become involved?

JW: Because of the common presence of extra-articular manifestations such as uveitis, IBD, and psoriasis among patients with axSpA, a close cooperation between different medical specialties—particularly rheumatologists, ophthalmologists, gastroenterologists, and dermatologists—is central for the care of this patient group. When faced with patients with spondyloarthritis who present with gastrointestinal (GI) tract complaints, rheumatologists should initiate a thorough examination of potential causes including (but not limited to) a detailed history regarding the nature of the symptoms, measurement of fecal calprotectin, and considerations regarding side effects of medication. In case of signs of bowel inflammation, patients should be referred to a gastroenterologist for an endoscopic examination and further management, since the presence of comorbid IBD will have important implications for the optimal choice of future antirheumatic drug therapy. But, as implicated by our present study, other GI conditions such as IBS may also be overrepresented in axSpA. Hence, patients with persistent GI complaints should be referred to gastroenterologists even in the absence of inflammatory signs in order to enable adequate examination and control of these symptoms.

RHEUM CON: What are the key takeaways for rheumatologists about the relationship between IBS and axSpA?

JW: IBS may be a previously overlooked, common comorbidity in axSpA, although this relationship needs further confirmation from other cohorts. The presence of IBS symptoms in patients with axSpA is most common among women and in patients with comorbid fibromyalgia. In our study, all standard, patient-reported spondyloarthritis outcome measures were significantly worse among the patients who reported IBS symptoms. Thus, similar to what has previously been shown regarding patients with comorbid fibromyalgia, the presence of IBS symptoms may contribute to worse self-perceived spondyloarthritis disease activity, a link entailing important treatment implications.

References:

1. Wallman JK, Mogard E, Marsal J, et al. Irritable bowel syndrome symptoms in axial spondyloarthritis more common than among healthy controls: is it an overlooked comorbidity? Ann Rheum Dis. 2020;79(1):159-161. doi:10.1136/annrheumdis-2019-216134.
2. Stolwijk C, van Tubergen A, Castillo-Ortiz JD, et al. Prevalence of extra-articular manifestations in patients with ankylosing spondylitis: a systematic review and meta-analysis. Ann Rheum Dis. 2015;74(1):65-73. doi:10.1136/annrheumdis-2013-203582.
3. Van Praet L, Van den Bosch FE, Jacques P, et al. Microscopic gut inflammation in axial spondyloarthritis: a multiparametric predictive model. Ann Rheum Dis. 2013;72(3):414-417. doi:10.1136/annrheumdis-2012-202135.
4. Olofsson T, Lindqvist E, Mogard E, et al. Elevated faecal calprotectin is linked to worse disease status in axial spondyloarthritis: results from the SPARTAKUS cohort. Rheumatology (Oxford). 2019;58(7):1176-1187. doi:10.1093/rheumatology/key427.
5. Sundström B, Wållberg-Jonsson S, Johansson G. Diet, disease activity, and gastrointestinal symptoms in patients with ankylosing spondylitis. Clin Rheumatol. 2011;30(1):71-76. doi:10.1007/s10067-010-1625-x.