Chronic Pelvic Pain

Chronic pelvic pain is pain in the lower abdomen or pelvis persisting for six months or more, severe enough to cause functional disability or prompt treatment. It is a syndrome rather than a diagnosis, and the single most important thing to understand about it is that it is frequently multifactorial — more than one contributing cause is the norm, and in a substantial proportion of cases no structural cause is ever identified.

Contributing causes fall into several groups:

• Gynaecological — endometriosis, adenomyosis, pelvic inflammatory disease and its adhesions, ovarian cysts, uterine fibroids, and pelvic congestion syndrome
• Urological — interstitial cystitis/bladder pain syndrome, recurrent urinary infection, chronic prostatitis in men
• Gastrointestinal — irritable bowel syndrome, inflammatory bowel disease, chronic constipation, diverticular disease
• Musculoskeletal — pelvic floor muscle dysfunction, sacroiliac and pubic symphysis problems, abdominal wall trigger points and nerve entrapment
• Neurological — pudendal neuralgia, nerve entrapment after surgery

Underlying all of these is the phenomenon of central sensitization, and it is what makes chronic pelvic pain behave differently from acute pain. Sustained nociceptive input alters processing in the dorsal horn and the brain, lowering the pain threshold and widening the receptive field. The result is pain that continues after the original trigger has resolved, spreads beyond the original site, and is accompanied by hyperalgesia and allodynia. This explains the common and frustrating clinical picture in which a lesion is removed and the pain remains.

Viscera share spinal segments with somatic structures, so pelvic pain is often poorly localized and referred to the back, buttock or thigh. A history of physical or sexual abuse, and coexisting depression or anxiety, are consistently associated and materially affect outcome — not because the pain is imagined, but because the same pathways modulate it.

The pain is typically described as dull, aching or dragging, punctuated by sharper episodes. It may be constant or cyclical; a clear relationship to the menstrual cycle points toward a gynaecological cause, while pain relieved by defecation suggests a bowel origin.

Associated features are common and help localize the problem: deep dyspareunia, post-coital aching, dysmenorrhea, urinary urgency and frequency, bowel habit change and bloating, and pain on prolonged sitting or standing. Sleep disturbance, fatigue, reduced physical activity, low mood and anxiety are almost universal in longstanding cases and are part of the syndrome rather than incidental to it.

Assessment aims to identify treatable contributors while avoiding repeated, unrevealing investigation — which in this condition can itself entrench the problem.

A careful history is the highest-yield step: the pattern and timing of the pain, its relationship to cycle, bladder, bowel and activity, prior surgery, and a sensitive enquiry into mood and abuse history. Examination should include abdominal palpation for trigger points, the Carnett test to distinguish abdominal wall from visceral pain, and a pelvic examination assessing for focal tenderness, masses, and pelvic floor muscle tone and tenderness.

Investigation is guided by the history: pelvic ultrasound, urinalysis and culture, and testing for chlamydia and gonorrhea. MRI is used where deep endometriosis or adenomyosis is suspected. Diagnostic laparoscopy identifies endometriosis and adhesions but is normal in a third to a half of cases, and a normal laparoscopy does not mean there is no pain — it means the cause is not one laparoscopy can see.

Chronic pelvic pain clusters strongly with other central sensitization syndromes — irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, migraine and temporomandibular disorder — and the presence of one raises the likelihood of others. Depression, anxiety and sleep disturbance are highly prevalent and worsen pain perception, making them treatment targets rather than side issues. Sexual dysfunction and relationship strain are common and often go unasked about.