Chapter 16: Pain of Urogenital Origin

INTRODUCTION

In order to evaluate and treat a woman with pain of urogenital origin, one must have a good understanding of chronic pelvic pain (CPP) in general. This encompasses a broad differential diagnosis spanning multiple organ systems. This chapter will present an overview of CPP, highlighting some of the more common etiologies, and providing a more expanded discussion of two disorders very commonly encountered by specialists in female pelvic medicine and reconstructive surgery, namely, interstitial cystitis/painful bladder syndrome (IC/PBS) and vulvodynia.

DEFINITION

Chronic Pelvic Pain

CPP traditionally has been defined as cyclic or noncyclic pain in the lower abdomen or pelvis, continuous or intermittent, of at least six months duration that limits daily activities or function.^1,2 However, no universally agreed upon definition exists. The term CPP implies that pain is in the “pelvis,” but its location can occur anywhere in the anatomic pelvis, including the abdominal wall from the navel caudad, as well as the low back or buttocks.¹ This wide breadth of location and consequently multiple possible sources of pain—both somatic and visceral—make the condition of CPP difficult to manage and study.

It is estimated that one in five women aged 18 to 50 report pelvic pain for 12 months or more.¹ Worldwide the prevalence of CPP is estimated at 2% to 24% of women.³ An analysis of a large primary care database in the United Kingdom found 38 per 1,000 women per year presented with CPP, which was similar to the rate of visits for asthma, 37 per 1,000.⁴ Of diagnoses made in these women, 20.2% were gynecologic, 30.8% urinary, and 37.7% gastrointestinal.⁴ Costs to the patient are great and include frustration and suffering often leading to inability to work and perform daily activities, strain on relationships, and negative impact on overall health and quality of life.

Endometriosis

Endometriosis is a common cause of CPP. Up to 87% of women with CPP are diagnosed with endometriosis. It is defined by the presence of endometrial glands and stroma outside the uterine cavity. Early menarche and prolonged menstrual cycles are risk factors for endometriosis, and women with a first-degree relative with endometriosis have seven to ten times the risk of developing endometriosis. Higher parity and longer lactation are associated with a lower risk. Endometriosis is estimated to affect 6% to 10% of reproductive age women.⁵

Interstitial Cystitis/Painful Bladder Syndrome

IC is one possible etiology of CPP. Once again, there is a lack of consensus regarding the definition and even the terminology to describe this syndrome. In general, it is a ...