The Evil Twins of Chronic Pelvic Pain Syndrome: A Systematic Review and Meta-Analysis on Interstitial Cystitis/Painful Bladder Syndrome and Endometriosis.

Background: Chronic pelvic pain is a debilitating condition affecting quality of life. Endometriosis is one of the leading causes of CPP, but recent studies highlighted the role of interstitial cystitis/bladder pain syndrome (IC/PBS) in causing CPP. Only some studies addressed the coexistence of these two conditions, which seems more frequent than what is supposed, leading to diagnostic delays and unnecessary surgeries. This systematic review aimed to evaluate the estimate of the prevalence of the comorbidity of endometriosis and IC/PBS.

Methods: We performed a systematic review of the literature indexed on PubMed, Scopus, ISI Web of Science, and Cochrane using a combination of keywords and text words represented by "painful bladder syndrome", "endometriosis", "interstitial cystitis", and "bladder pain syndrome". We performed a meta-analysis of the results.

Results: The meta-analysis shows that the coexistence of endometriosis and IC/PBS in women with CPP ranged from 15.5% to 78.3%, which is higher than the prevalence of IC/PBS in the general population.

Conclusions: Prevalence data about the coexistence of endometriosis and IC/PBS are highly heterogeneous, probably due to the paucity of available data. However, in cases of endometriosis unresponsive to treatment, other reasons for CPP (such as IC/PBS) need to be ruled out.