This review discusses the etiologies, evaluations and management strategies for what can often be a frustrating condition for patients.
©RFBSIP - stock.adobe.com
Chronic pelvic pain is a common chief complaint, accounting for approximately 10% of referrals to a gynecologist, 20% of hysterectomies and 40% of diagnostic laparoscopies.1 The complex and often multifactorial nature of the disorder makes management challenging for patients and providers alike, which can frequently lead to both provider and patient dissatisfaction.2 This straightforward review of the most common etiologies, evaluation, and opioid-sparing management strategies is intended to demystify the disorder and empower providers to improve women’s quality of life through practical, evidence-based strategies.
Chronic pelvic pain has traditionally been defined as noncyclic pain of 6 months duration that localizes to the anatomic pelvis, anterior abdominal wall at or below the umbilicus, the lumbosacral back or the buttocks, and is of sufficient severity to cause functional disability or lead to medical care.3 This broadly defined anatomic region necessitates an equally broad differential diagnosis, with potential sources of pain not limited to the genitourinary system. Gastrointestinal, neurological, and musculoskeletal sources of pain, with which the general ob/gyn may be less familiar, must also be considered. Adding to this complexity, chronic pain syndromes usually have a central nervous system (CNS) component: input from peripheral sources is more readily passed along through the spinal cord to higher cortical centers, leading to perceived pain that can appear disproportionate to the peripheral stimulus. This combination of multiple anatomic structures over which no individual medical specialty has comprehensive knowledge, and alterations in central pain processing belie the need for a multidisciplinary approach.
Historically, the severity of chronic pelvic pain was felt to be directly proportional to the extent of pathology. However, studies using diagnostic laparoscopy have shown that the extent of pelvic pain does not correlate well with the extent of endometriosis or adhesions present in the pelvis.4 This observation is consistent with current thinking about chronic pain syndromes in that, unlike acute pain, chronic pain involves both CNS and peripheral nervous system pathways. Alterations in central pathways are highly dependent on psychosocial influences, with anxiety and stress suspected to amplify the experience of pain, independent of the magnitude of the peripheral stimulus.5,6 In addition, there is a strong association between a history of physical or sexual abuse and development of chronic pelvic pain. This relationship could be causal, related to sensitization via alterations in central processing, or coincidental. Regardless of the relationship, concurrent treatment of these psychosocial comorbidities plays a key role in treatment success.7,8
Given the prevalence of comorbid anxiety, depression, and sexual abuse with chronic pelvic pain, successful treatment relies heavily upon establishing a trusting, therapeutic relationship with these patients. A small qualitative study of the attitudes of patients with chronic pelvic pain toward their care revealed four main themes, which can be reframed as a useful guide for establishing a productive treatment relationship9:
Providing a sense of personalized care and helping patients to feel understood and taken seriously often translates to a significant amount of face-to-face time, which can be challenging to accommodate in a busy office practice. However, the additional time spent at the initial visit can often be recouped because future visits are shorter and less frequent. In fact, a patient’s favorable impression of the initial visit has been shown to be associated with a higher likelihood of complete resolution of pain.10 Helping patients suffering from chronic pain to feel they are being taken seriously requires special attention, as patients are often sensitized to even subtle messages from providers that their pain is “all in their head.” It is therefore helpful to provide tangible examples to patients of how both central and peripheral pathways are involved in our pain experience, such as the common experience of noting a laceration only long after the injury may have occurred, or times in which a stubbed toe resulted in a surprisingly intense experience of pain.
As is true with most other conditions, the etiology of chronic pelvic pain can be consistently identified through a detailed history and physical exam, provided the starting point is a reasonable list of potential diagnoses. The broad anatomic area that falls under the definition of pelvic pain requires an equally broad list of potential conditions, which can often be overwhelming. Therefore, it may be useful to organize the differential diagnosis anatomically into the uterus, cervix, fallopian tubes, ovaries, vagina, bladder, ureters, rectum, intestines, pelvic bones, pelvic musculature, and pelvic nerves. The character of a patient’s pain may help to further narrow the differential diagnosis, given the two different physiologic pathways that can be involved in pelvic pain: visceral and somatic (Table 1).11
While an exhaustive list of etiologies of pelvic pain is too expansive to fully itemize,12 only a handful of conditions account for the majority of chronic pelvic pain, with multiple causes often present concurrently (Table 2).12-15 For the general ob/gyn, the ability to diagnose and appropriately treat or refer these conditions would make a tremendous impact for most women who suffer from chronic pelvic pain.
The aforementioned extended time at the initial visit may best be used to collect a detailed history, going back to our training roots and eliciting the seven dimensions of the symptom (Table 3) and to perform a detailed exam. In addition, it is paramount to ask the patient what she thinks her pain may represent. Patients often fear that their pain is due to malignancy or some as-yet-undiscovered and potentially lethal condition. Often, these anxieties can be readily assuaged at the initial assessment by taking the time to explain the rationale for the most likely diagnosis. Failure to identify these concerns can significantly impair further treatment.
Screening for interstitial cystitis quickly identifies a subset of patients who suffer from a non-gynecologic condition that frequently presents with chronic pelvic pain. Urinary frequency is often the first symptom. Evaluating for pain that improves with defecation or onset of symptoms associated with changes in frequency or form of stool will screen for irritable bowel syndrome. Evaluation should also include assessment of the patient’s psychosocial situation, including sexual function, presence of depression, post-traumatic stress disorder, and any history of physical or sexual abuse. The International Pelvic Pain Society (IPPS) has a detailed history and physical examination form available for download in multiple languages.
A careful abdominal exam, which includes light and deep palpation, will identify neuralgias. Single-digit palpation with both flexion and relaxation of the rectus abdominus muscles will distinguish abdominal wall pathology from intra-abdominal sources: focal pain that worsens with engagement of the abdominal muscles is highly likely to be related to the abdominal wall, whereas pain that improves when the rectus abdominus muscles are flexed may suggest a visceral source. Evaluation of spinous processes and paraspinal muscle tenderness along with lower extremity strength, sensation, and range of motion can elucidate additional musculoskeletal sources of pain.15
Before starting the pelvic exam, the providers should empower the patient to request a break or ask that the exam be concluded at any time. Provided adequate trust is established between provider and patient, in our experience, very rarely is it impossible to complete pelvic exams in patients with chronic pelvic pain, despite the high prevalence of sexual abuse and trauma in these women.
Begin the exam with external inspection and test for provoked and unprovoked vulvodynia through light palpation with a Q-tip. A single-digit internal exam with palpation of the urethra, obturator internus, bladder base, rectum, levator ani, anterior and posterior cul-de-sac and uterosacral ligaments, in addition to palpation of the uterus and adnexa is essential to identify the many possible sources of pain. With palpation of each area, it is also important to clarify with the patient if what she is feeling is the same pain she wanted evaluated because pain produced on pelvic exam often is not experienced in daily life.
Pelvic ultrasound is not indicated for all patients but should be considered in the presence of uterine or adnexal tenderness, or if the pelvic exam is limited secondary to patient habitus. Laboratory evaluation is rarely indicated, except to address specific symptoms or exam findings. Diagnostic laparoscopy is common for evaluation of chronic pelvic pain, despite limited data supporting its use. Given the relatively poor correlation between intraabdominal findings at time of laparoscopy and the extent of symptoms, diagnostic laparoscopy should be reserved for patients with known pathology by ultrasound, or in patients in whom endometriosis is suspected, but who do not respond to or cannot tolerate a trial of hormonal therapy.
Responsible prescribing practices
Multiple studies have demonstrated the efficacy of a multidisciplinary approach to treatment of chronic pelvic pain.7,16,17 The decision to refer for care by another provider should be based on local resources and provider experience. While general ob/gyns are well trained to manage endometriosis, treatment of the other three most common diagnoses-interstitial cystitis/painful bladder syndrome, irritable bowel syndrome, and musculoskeletal disorders-may be outside their purview. In addition, for the subset of patients with other, less common etiologies of chronic pelvic pain, referral to a chronic pelvic pain specialist should be considered. The IPPS maintains a directory of pelvic pain specialists, searchable by zip-code.
For endometriosis, continuous combined or progesterone-only oral contraceptives (OCs) remain first-line treatment. Setting clear expectations about possible side effects is important, as is counseling patients that it make take 2 to 3 months of treatment for their pain to improve. Patients whose pain doesn’t respond or responds inadequately to initial therapy should be evaluated further with laparoscopy to confirm the diagnosis and potentially relieve symptoms. Once the diagnosis is confirmed, treatment for endometriosis should be primarily medical with either ongoing continuous OCs, or one of several evidence based second-line therapies (Table 4).18-23
Suspected interstitial cystitis should prompt a urinalysis and culture to rule out urinary tract infection and then, if feasible, the patient should be referred to a urogynecologist. These subspecialists are well-equipped to not only make this diagnosis, but also to evaluate and treat commonly related diagnoses, such as overactive bladder syndrome, urinary incontinence, and pelvic organ prolapse. Patients can be given a list of common bladder irritants and asked to sequentially eliminate each from their diet and maintain a symptom diary in preparation for their consultation. A helpful patient handout is available from the American Urogynecologic Society. A treatment guide from the American Urological Association may be helpful in cases where referral to a urogynecologist is not possible.24
Irritable bowel syndrome is highly likely in patients with chronic pelvic pain who have bowel symptoms. However, as with painful bladder syndrome, it is important to rule out other more serious conditions prior to settling on this diagnosis. “Red flag” symptoms (Table 5) should prompt consideration of alternative diagnoses or referral to a gastroenterologist. In the absence of these concerning symptoms, the ROME II criteria25 can be used to make the diagnosis. A practical treatment guide, including a patient handout, is available from the American Academy of Family Physicians.
Musculoskeletal etiologies of pelvic pain are exceedingly common and can be readily elicited by careful exam, as described. While levator ani or obturator internus myalgia can be a primary cause of chronic pelvic pain, pelvic myalgia is more often due to chronic muscle contraction and subsequent injury in response to other painful stimuli. In addition to treating the other source(s) of pain, pelvic physical therapy is highly effective, with one study suggesting that about two-thirds of patients can expect moderate or marked improvement in pain symptoms26 and another demonstrating that patients rated the treatment efficacy as 8/10.27 The American Physical Therapy Association maintains a registry of physical therapists that is searchable by zip code and area of expertise (aptaapps.apta.org/findapt/SearchResults.aspx).
A significant proportion of patients who report chronic pelvic pain will have physical exam findings in the abdominal wall consistent with a trigger point, which has been defined as a focus of hyperirritability in a tissue that, when compressed, is locally tender and, if sufficiently hypersensitive, gives rise to referred pain and tenderness, and sometimes to referred autonomic phenomena and distortion of proprioception.28 While much controversy continues to surround this phenomenon, a trial of self-massage to the point of moderate discomfort has been proposed as a low-risk, potentially effective intervention. For patients in whom 2 to 3 weeks of self-massage has proven to be ineffective, a trial of trigger point injections could be considered.29,30 There are many variations in technique, though one example can be found here: https://emedicine.medscape.com/article/1997731-technique. In our clinic, a weekly series of three to four injections of 3 to 5 mL of 0.25% bupivacaine into the area of tenderness in the abdominal wall, low back, or pelvic floor muscles often provides significant relief. If there is no response after the third or fourth injection, consider alternative treatments.
Given the known role of psychosocial factors in modulating central pain processing, these comorbidities should be treated concurrently with evaluation and treatment of peripheral sources of pain. Delaying management of anxiety, depression, and social stressors until after a trial of treatment of peripheral sources of pain is likely to result in decreased treatment efficacy and can often lead to the patient feeling dismissed. Any plan for referral should be a shared decision with the patient, with the discussion focusing on the role of both peripheral and central pain processing in the patient’s overall pain experience. Developing a referral network of providers with expertise in pharmacologic management of depression, anxiety, and PTSD, as well as provision of counseling services will greatly bolster treatment efficacy and likely provider and patient satisfaction.
In 2015, there were 20,101 overdose deaths related to prescription pain medications; nearly double the deaths related to heroin.31 We cannot take the opioid epidemic lightly. However, we should not overlook careful prescription of opioids as an option for pain management. Multiple studies have demonstrated that opioids decrease acute pain by about 30%.32,33 Their lasting effect on chronic pain is much more controversial. Because most placebo-controlled randomized clinical trials evaluating opioids for pain management are ≤6 weeks in duration, there is insufficient evidence to guide opioid prescribing for chronic pain.
Chronic pelvic pain is a complex, often multifactorial condition that afflicts many women and poses a significant challenge to our healthcare system. Evaluation should include a comprehensive history and physical with consideration for gynecologic and non-gynecologic sources of pain. Practical, non-opioid-based treatments exist for the most common causes of chronic pelvic pain, which should be provided in concert with therapy for any co-existing psychosocial stressors. Opioids should be prescribed only after careful consideration and with patient safety in mind. While challenging, treatment of chronic pelvic pain can be rewarding and have a lasting impact on our patients’ quality of life.
The authors report no potential conflicts of interest with regard to this article.