Highlights in basic autonomic neurosciences: Cross-organ sensitization between the bladder and bowel

Abstract

Chronic pelvic pain (CPP) and visceral pain (VP) are common, debilitating conditions which present a major challenge to health care providers around the world. Both are characterised by generalised, diffuse pain sensation, coupled with alterations in organ function. Often CPP and VP arise following the resolution of an acute infection and in some cases can induce functional alterations and pain from a different unaffected region. This is consistent with the concept of cross-organ sensitization. Clinical data provides compelling evidence for cross-organ sensitization between the bladder and bowel. Roughly 30% of patients presenting with irritable bowel syndrome (IBS) also present with bladder symptoms such as increased or incomplete bladder emptying, urgency, nocturia and pain (Malykhina, 2007). The same has also been reported in patients with overactive bladder syndrome (OABS) and interstitial cystitis/painful bladder syndrome (IC/PBS) who exhibit symptoms of IBS (Whorwell et al., 1986). Cross-organ sensitization has also been demonstrated between the uterus, pelvic urethra and vagina and in males cross-organ sensitization between the prostate and other pelvic organs has also been suggested. Despite the prevalence of CPP, VP and cross-organ sensitization, the underlying mechanisms are not fully understood.