Interstitial cystitis/bladder pain syndrome (IC/BPS) is now recognized as a common etiology in women with chronic pelvic pain. The prevalence of this syndrome ranges from 2.7% to 6.5%, which translates to between 3.3 and 7.9 million women in the United States.1 The true accuracy of this data is limited by the varying definitions of IC/BPS and the underdiagnosis of patients.2 Fortunately, simple and effective treatments are now available. Most patients with IC/BPS can be treated using efficient office-based algorithms to achieve significant relief of their symptoms. Diagnosing and establishing a treatment plan, however, can be daunting for practitioners inexperienced in treating patients with IC/BPS. Efficient diagnosis and effective treatment for IC are explored and reviewed here.
The term “IC” was first coined in 1887 and has evolved into the entity we know today.3 The simplest definition of IC/BPS as provided by the American Urological Association (AUA) is “an unpleasant sensation (pain, pressure, or discomfort) perceived to be related to the urinary bladder, associated with lower urinary tract symptoms of more than six weeks duration, in the absence of infection or other identifiable causes.”4
In 1988, the National Institute of Diabetes and Digestion and Kidney Diseases (NIDDK) developed rigorous diagnostic criteria for research on IC. Unfortunately, these criteria became the de facto definition for diagnosis despite the controversy that many patients with IC symptoms lack classic cystoscopic findings (glomerulations or Hunner’s ulcers). It is estimated that the NIDDK criteria miss 60% of patients with IC.2 In response to this, the International Continence Society recommended using the term “BPS,” which includes the more relaxed definition described previously.5
Currently, no ICD-9/10 code for BPS exists. The ICD-9/10 codes for IC are listed in Table 1. For simplicity and consistency, consider using the term IC in discussions with patients and for clinical documentation and billing. For the remainder of this article, IC will be used to refer to patients with IC and/or BPS.
Although the exact etiology of IC is unknown and is likely multifactorial, the leading theory can be used as a model to understand how symptoms occur and why certain treatments can be effective (Figure 1). The glycosaminoglycan (GAG) layer normally coats the urothelium and acts as a nonspecific defense mechanism against infection and urinary irritants.6 This layer normally contains heparin; it is believed that the absence of heparin causes an increase in GAG layer permeability. Urinary irritants then penetrate the urothelium leading to tissue damage, pain, and hypersensitivity through activation of the underlying nerves and muscle.7 Activation of bladder mast cells may also play a role in the propagation of ongoing bladder damage.8
Another way to conceptualize IC is as a visceral pain syndrome. Compared with somatic nerves, visceral nerves in the pelvis transmit signals more slowly, are mapped more poorly in the central nervous system (CNS), and overlap with innervation of other pelvic organs. In addition, non bladder-related syndromes that cause pelvic pain can initiate visceral and CNS sensitization. Chronic pelvic neural upregulation results in poorly localized and poorly characterized symptoms. Subsequently, bladder nerve stimulation can be perceived as bladder origin pain. Irritable bowel syndrome (IBS) is another common visceral pain syndrome. Up to 48% of patients with IC also have symptoms consistent with IBS.9 Treatments for IC directly or indirectly are designed to help downregulate the visceral nerve signals in the pelvis.
Patients with frequent symptoms of urinary tract infection (UTI) but repeated negative cultures should be evaluated for IC. It is also important to consider screening all patients presenting with subacute or chronic pelvic pain for IC.
Two validated screening tools are available, the Pelvic Pain and Urgency/Frequency (PUF) patient symptom scale and the O’Leary-Sant IC symptom and problem index.10 These short questionnaires can be administered to patients on intake. Higher screening scores correlate most closely with the diagnosis of IC.11 Screening questionnaires are available online through the Interstitial Cystitis Association (ICA) (see Resources).