Chronic Pelvic Pain

OVERVIEW

Chronic Pelvic Pain (CPP) in women is non-cyclical or cyclical pain located in the lower abdomen, pelvis, or pelvic girdle, lasting for >= 6 months, causing functional disability or requiring medical intervention.

Pathophysiologic Nature: Multi-factorial condition frequently involving complex overlap between gynecological, urological, gastrointestinal, musculoskeletal, neurological, and central pain sensitization (central sensitization syndrome) pathways.

Chronic pelvic pain is a symptom, not a single disease diagnosis. Over 40% of women with CPP have more than one contributing etiology (e.g., Endometriosis co-existing with Interstitial Cystitis or Myofascial Pelvic Pain). A multidisciplinary approach is required.

APPROACH

Step 1: Emergency Triage & Red Flag Screening (Rule Out Acute / Life-Threatening Crisis)

Acute Worsening + Unstable Vitals / Severe Hemorrhage: -> Rule out Ruptured Ectopic Pregnancy, Ruptured Ovarian Cyst, Hemoperitoneum.
Acute Severe Pain + Peritoneal Signs (Guard/Rebound) + Fever: -> Rule out Pelvic Inflammatory Disease (PID) / Tubo-Ovarian Abscess (TOA) or Appendicitis.
Sudden Onset Severe Pain + Nausea/Vomiting: -> Rule out Adnexal / Ovarian Torsion (Emergency surgical laparoscopy required).
Post-menopausal Bleeding + Pelvic Pain / Mass: -> Suspect Endometrial or Ovarian Malignancy.

Step 2: Anatomical & Systemic Screening

Gynecological: Cyclical dysmenorrhea, deep dyspareunia, abnormal uterine bleeding -> Endometriosis, Adenomyosis, Fibroids.
Urological: Dysuria, urinary frequency, urgency, pain relieved by voiding -> Interstitial Cystitis / Bladder Pain Syndrome (IC/BPS).
Gastrointestinal: Altered bowel habits (diarrhea/constipation), bloating, pain relieved by defecation -> Irritable Bowel Syndrome (IBS).
Musculoskeletal / Neuropathic: Pain aggravated by movement/weight-bearing, focal trigger points on levator ani palpation, burning/shooting pain in pudendal nerve distribution -> Pelvic Floor Dysfunction / Pudendal Neuralgia.

Step 3: Clinical Decision Branching

Pelvic Mass / Abnormal Ultrasound Findings: -> Targeted gynecological management / surgical referral.
Cyclical Pain + Deep Dyspareunia + Normal Imaging: -> Empirical Trial of Hormonal Suppression (e.g., Combined Oral Contraceptive Pill or Progestins) for suspected Endometriosis.
Non-Cyclical Pain + Diffuse Pelvic Tenderness + Myofascial Trigger Points: -> Pelvic Floor Physiotherapy + Central Pain Neuromodulation.

A completely normal pelvic ultrasound does NOT rule out Endometriosis. Superficial peritoneal endometriosis lesions are invisible on standard ultrasound. Laparoscopy remains the gold standard diagnostic tool for superficial peritoneal disease.

DIFFERENTIAL DIAGNOSIS

Gynecological Causes (~50–60% of cases):

Endometriosis:
- Distinguishing features: Classic triad of Severe Dysmenorrhea, Deep Dyspareunia, and Infertility; dyschezia during menses; pain peaks just before/during menstruation.
Adenomyosis:
- Distinguishing features: Multiparous women age > 30–40; severe dysmenorrhea + heavy menstrual bleeding (menorrhagia); symmetrically enlarged, soft, tender “globular” uterus on pelvic exam.
Pelvic Venous Disorders (Pelvic Congestion Syndrome):
- Distinguishing features: Dull, aching pelvic heaviness worse at the end of the day, post-coital pain, presence of vulvar/perineal varicosities.
Chronic Pelvic Inflammatory Disease (PID) / Adhesions:
- Distinguishing features: History of acute PID or sexually transmitted infection; constant deep ache, cervical motion tenderness.

*Transvaginal Ultrasound and MRI Features of Adenomyosis. Source: JCPSP | Journal of College of Physicians and Surgeons Pakistan*

Non-Gynecological Causes (~40–50% of cases – Frequently Overlooked):

Interstitial Cystitis / Bladder Pain Syndrome (IC/BPS):
- Distinguishing features: Suprapubic/pelvic pain associated with bladder filling, relieved temporarily by voiding; severe urinary frequency/urgency; sterile urine cultures.
Irritable Bowel Syndrome (IBS):
- Distinguishing features: Abdominal/pelvic pain associated with changes in stool frequency or form; bloating; symptoms improved following defecation.
Pelvic Floor Myofascial Pain / Levator Ani Syndrome:
- Distinguishing features: Constant aching pain, feeling of “fullness in vagina/rectum”; reproducible focal tenderness on palpation of levator ani or obturator internus muscles.
Pudendal Neuralgia:
- Distinguishing features: Burning, lancinating pain in clitoral, vulvar, or perineal region; worse with sitting, relieved by standing or sitting on a toilet seat.

Think of the “Painful Bladder Rule”: If a patient presents with chronic pelvic pain and urinary frequency/urgency, and urine cultures are repeatedly negative, suspect Interstitial Cystitis / Bladder Pain Syndrome.

INVESTIGATIONS

First-Line / Bedside & Laboratory Diagnostics:

Bimanual & Speculum Pelvic Exam: Evaluate uterine size/mobility, uterosacral ligament nodularity (endometriosis), cervical motion tenderness, and palpate pelvic floor muscles for myofascial trigger points.
High-Purity Transvaginal Ultrasound (TVUS) – Deep Endometriosis Protocol: Gold standard initial imaging. Highly sensitive for detecting Endometriomas (“ground-glass” appearance), Adenomyosis, Fibroids, and Deep Infiltrating Endometriosis (DIE) involving uterosacral ligaments or rectovaginal septum.
High-Vaginal / Endocervical Swabs (PCR): Screen for Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium.
Mid-Stream Urine (MSU) & Culture: Exclude recurrent urinary tract infection.
Serum CA-125: Optional; elevated in severe endometriosis, adenomyosis, or ovarian malignancy (nonspecific).

Targeted / Specialized Workup:

Pelvic MRI (Dedicated Endometriosis Protocol): Excellent secondary imaging tool to delineate deep infiltrating endometriosis, complex adenomyosis, or pelvic nerve entrapment when TVUS is equivocal.
Diagnostic Laparoscopy: Gold standard for direct visualization and histopathological confirmation of superficial peritoneal endometriosis and lysis of pelvic adhesions.
Flexible Cystoscopy & Hydrodistention: Used to evaluate for Hunner’s lesions in suspected Interstitial Cystitis.

Transvaginal ultrasound should be performed using a specialized “deep endometriosis protocol” (evaluating organ mobility and sliding signs) to accurately detect rectovaginal or uterosacral deep infiltrating disease.

CRITICAL MANAGEMENT

First-Line Pharmacological Management (Gynecological / Cyclical Pain):

Hormonal Suppression (First-Line for Endometriosis/Adenomyosis):
- Combined Oral Contraceptive Pills (continuous regimen to induce amenorrhea) OR
- High-dose Progestins (e.g., Dienogest 2 mg daily, Medroxyprogesterone) OR
- Levonorgestrel Intrauterine System (LNG-IUS / Mirena) -> First-line for Adenomyosis.
GnRH Agonists / Antagonists:
- Leuprorelin / Goserelin (with add-back HRT) or Oral GnRH Antagonists (e.g., Elagolix) for severe/refractory endometriosis.

Neuromodulation for Central Sensitization & Neuropathic Pain:

Gabapentinoids & Antidepressants: Amitriptyline (10–25 mg nocte) or Gabapentin/Pregabalin for central pain processing, pudendal neuralgia, or IC/BPS.

Non-Pharmacological & Multidisciplinary Core Therapies:
- Pelvic Floor Physical Therapy: Specialized down-training, manual release, and biofeedback for hypertonic pelvic floor dysfunction.
- Psychological Interventions: Cognitive Behavioral Therapy (CBT) and Acceptance and Commitment Therapy (ACT) to address pain processing, secondary anxiety, and coping strategies.

Avoid repeated diagnostic laparoscopies for chronic pelvic pain when previous procedures were negative for structural pathology. Repeated surgeries increase adhesion formation and can exacerbate central pain sensitization.