E0 ConsensusModerate confidencePEM not requiredSystematic-ReviewPeer-reviewedMachine draft
Standard · 3 min
Evidence for overlap between urological and nonurological unexplained clinical conditions.
Bullones Rodríguez, María Ángeles, Afari, Niloofar, Buchwald, Dedra S et al. · The Journal of urology · 2013 · DOI
Quick Summary
This study looked at how often people with unexplained urinary and bladder conditions also have other unexplained pain and fatigue conditions like fibromyalgia and ME/CFS. Researchers reviewed over 1,000 published studies and found that these conditions often occur together in the same person—sometimes up to 79% of people with chronic pelvic pain also had irritable bowel syndrome symptoms. This suggests these conditions may share common underlying causes rather than being completely separate diseases.
Why It Matters
ME/CFS patients frequently experience comorbid unexplained conditions including urological and gastrointestinal symptoms. Understanding the extent and nature of these overlaps supports a systems-level perspective of ME/CFS pathophysiology rather than isolated organ dysfunction, potentially redirecting research toward common underlying biological mechanisms.
Observed Findings
Considerable comorbidity documented between urological and nonurological unexplained conditions across published literature
Irritable bowel syndrome showed the most robust overlap with urological unexplained syndromes
Comorbidity estimates between chronic pelvic pain and IBS symptoms reached up to 79% in some studies
Included studies used varying case definitions and control selection methods
Shared features identified across conditions: pain, fatigue, disability disproportionate to examination findings, inconsistent laboratory abnormalities, and associations with stress
Inferred Conclusions
Urological and nonurological unexplained clinical conditions share substantial symptomatic and epidemiological overlap suggesting possible common pathophysiological mechanisms
The magnitude and true nature of comorbidity remain unclear due to methodological inconsistencies in existing literature
Future research requires standardized case definitions and rigorous study designs to clarify mechanisms underlying the observed overlaps
Remaining Questions
What are the shared biological or pathophysiological mechanisms underlying comorbidity between urological and nonurological unexplained conditions?
What This Study Does Not Prove
This review does not establish causation between conditions or identify specific biological mechanisms driving comorbidity. The substantial methodological heterogeneity across included studies means the reported comorbidity estimates should be viewed cautiously, and the findings reflect correlation rather than mechanistic understanding.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →