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Diagnosing Chronic Pelvic Pain


 

Too often, women with chronic pelvic pain will have a barium enema to rule out a gastrointestinal cause, an intravenous pyelogram to rule out urinary tract disease, and a host of other diagnostic tests that are neither efficient nor effective because they have not been driven specifically by the findings of a history and physical exam. Most gastrointestinal causes of pelvic pain, in fact, cannot be diagnosed by a barium enema, and most urologic causes cannot be determined through an IVP. The same holds true for other tests.

Such a rule-out approach may seem appropriate up front, but it actually is much less efficient—and quite often less accurate—than a stepwise, deliberate approach to history-taking and physical examination.

With the correct approach, we can successfully evaluate most patients with chronic pelvic pain in a 45-minute visit—which is an achievement, considering that many disorders of the reproductive tract, gastrointestinal system, urologic organs, musculoskeletal system, and psychoneurologic system may be associated with the disorder.

Behind the Diagnostic Approach

After years of treating patients with chronic pelvic pain, I still am struck by the fact that among women of reproductive age, the disorder has about the same prevalence as do asthma, migraine headache, and low-back pain. It is a significant cause of all referrals to gynecologists, and the etiology is usually not immediately discernible. More often than not, chronic pelvic pain is caused by or associated with several diagnoses or disorders.

One woman, for instance, might have endometriosis, irritable bowel syndrome, and emotional stresses, all of which could be contributing to her chronic pelvic pain.

We lack a universally accepted definition of chronic pelvic pain, but we come closest, I believe, with a definition described in a practice bulletin published by the American College of Gynecologists and Obstetricians in 2004.

The definition is based primarily on the duration, location, and severity of the pain. It says that chronic pelvic pain is noncyclic pain of 6 or more months' duration that is localized to the true anatomical pelvis; the anterior abdominal wall at or below the umbilicus; the lumbosacral back; or the buttocks. The pain must be severe enough to cause functional disability or require medical care.

Some experts include chronic vulvar pain in their definition of chronic pelvic pain, but many do not—and the latter sentiment is reflected in ACOG's definition. According to the bulletin, approximately 15%–20% of women aged 18–50 years have chronic pelvic pain that lasts longer than 1 year.

It is less clear what proportions of women with chronic pelvic pain have specific diagnoses. We do know, however, that the gastrointestinal tract and urinary tract are just as important—if not more important—than the reproductive tract in its diagnosis. One study using a large, primary care database in the United Kingdom found that diagnoses related to the GI and urinary tracts were significantly more common than gynecologic diagnoses (approximately 38% GI, 31% urinary, and 20% gynecologic).

Again, the message for us is significant: We need to conduct a comprehensive review, through a history and physical exam, of all the systems—not only the reproductive tract—that are potentially involved in chronic pelvic pain.

The History and Exam

One of the fundamental components of the diagnostic approach is a pelvic pain intake questionnaire. Questionnaires are so commonly used in medicine today that they generally are well received by patients, and although they are not at all meant to take the place of listening to the patient tell her story, they can be quite helpful in securing details of your patient's obstetric and other medical and psychosocial history as well as the location, severity, quality, and timing of her pain. The International Pelvic Pain Society offers a useful form that can be downloaded free of charge.

It can also be useful to ask your patient to mark the location of her pain on a pain map, indicating whether it is external or internal, and whether it is sharp, dull, numb, or prickly. Other evaluation instruments, such as the visual analog scale, may also be used to assess pain severity. In addition, it can be useful to ask the patient how long the pain lasts when it occurs, how much it affects her daily life, and how the pain has changed over time.

When it comes to the physical exam of a patient with chronic pelvic pain, we need to think a little differently than we would in other scenarios and with other classic exam techniques. One of our major goals with chronic pelvic pain is to detect exact locations of tenderness and correlate these with areas of pain, so we need to think of our exam as an attempt to map the patient's pain.

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