Chronic pelvic pain Part I: prevalence, etiology, diagnosis

Townsend Letter for Doctors and Patients, Nov, 2006 by Tori Hudson

Chronic pelvic pain in women can present one of the more difficult diagnostic challenges in women's health. Even once diagnosed, the cause is often difficult to manage, let alone cure. Numerous gynecologic and nongynecologic disorders are associated with chronic pelvic pain. In cases of a clear etiology, treatment is focused on alleviating the pain and treating the cause. In the absence of a clear cause for the pain, treatment then needs to be directed toward alleviating the symptoms. This article will provide an overview and differential diagnosis of chronic pelvic pain. In addition, in part II, in the next issue, I will attempt to offer treatment options for many of the conditions causing chronic pelvic pain, including primary dysmenorrhea, endometriosis, adenomyosis, chronic PID, interstitial cystitis, irritable bowel syndrome, pelvic adhesions, and pelvic floor dysfunction.

In taking a holistic approach to chronic pelvic pain, we will need not only to keep in mind how numerous body systems can influence and result in chronic pelvic pain, but we will also need to appreciate the influence of stress and psychological traumas and recognize different adaptations to those traumas and different thresholds of pain.

Definition and Incidence

There is no accepted definition of chronic pelvic pain, but one proposed definition is "noncyclic pain of six or more months that is localized to the pelvic, anterior abdominal wall at or below the umbilicus, the lumbosacral back, or the buttocks and is severe enough to cause functional disability or lead to medical care." Physical findings are often lacking and do not negate the significance of the pain. On the other hand, a normal examination does not rule out pelvic pathology. Chronic pelvic pain is far more common than one might expect, reaching a surprising 15-20% of women aged 18-50.

Causes of Chronic Pelvic Pain

Pelvic pain can be generally divided into two categories: gynecological and nongynecological. It can be tempting to think of chronic pelvic pain as only due to gynecological causes, but this would be incorrect and delay diagnosis and treatment much of the time. Sources of pelvic pain include the organs of the reproductive, genitourinary, and gastrointestinal systems; the bones of the pelvis, and ligaments, muscles and fascia; and psychological or neurological diseases.

A complicating factor is that many women with chronic pelvic pain have more than one disease that leads to their pain. Perhaps not surprisingly, women with diagnoses that involve more than one cause have greater pain than women with only one source. Women with chronic pelvic pain are more likely to have dysmenorrhea and dyspareunia than women in the general population. The severity of dyspareunia and dysmenorrhea is greater in women who have gastrointestinal and urologic symptoms than in those who do not.

Women at Risk of Chronic Pelvic Pain

Women with chronic pelvic pain have no differences in terms of age, race, ethnicity, education, socioeconomic status, or employment status. However, women with chronic pelvic pain may be slightly more likely to be separated or divorced. Though age is not a specific risk factor, women with chronic pelvic pain tend to be of reproductive age, even though women develop chronic pelvic pain at all ages. Some of the etiologies of pelvic pain are more prevalent at different ages.

Physical and Sexual Abuse

Studies have suggested that many chronic pain disorders can be associated with a history of physical and sexual abuse. (1,2) Studies have also found that 40%-50% of women with chronic pelvic pain have a history of physical or sexual abuse. (3-7) While we don't really understand the mechanism, it appears this link may be either psychological or neurological.

Pelvic Inflammatory Disease

Acute pelvic inflammatory disease can commonly lead to chronic pelvic pain. It has been estimated that this happens 18-35% of the time. The mechanism for this is not known, but theories include pelvic adhesions resulting from the acute infection.

Endometriosis

Endometriosis is a direct cause of pelvic pain and can also indirectly put women at increased risk of pelvic pain due to other etiologies. Women with endometriosis have increased kidney stones and more severe pain episodes of kidney stones when compared to women without endometriosis. (8) Thirty-three percent of women with chronic pelvic pain have laparoscopic-diagnosed endometriosis; 24% of laparoscopies for chronic pelvic pain reveal adhesive disease; and 35% have no visible pathology. (9)

Interstitial Cystitis

Interstitial cystitis (IC) is typically characterized by frequent urination and urgency of urination. Women with IC are at significantly increased risk of chronic pelvic pain, and chronic pelvic pain is, in fact, reported by up to 70% of women with IC. Occasionally, it is the presenting chief complaint. IC is perhaps the most commonly under-diagnosed cause of chronic pelvic pain.

Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is one of the most common conditions associated with chronic pelvic pain. IBS occurs much more frequently in women, and more often in women with chronic pelvic pain. IBS symptoms are found in 50%-80% of women with chronic pelvic pain. (10)