Chronic pelvic pain

Chronic pelvic pain is pain in the lower abdomen or pelvis that lasts at least 6 months, is not confined to menstruation, intercourse or pregnancy, and is severe enough to cause functional disability or need treatment.

It is a symptom with gynaecological, urological, gastrointestinal, musculoskeletal, neurological and psychological contributors, and several often coexist.

The main clinical point is to look for a treatable organ disease, recognise central sensitisation and pelvic floor dysfunction, and treat in a structured, multimodal way rather than by repeated surgery.

Clinical relevance. It is common in women, often under diagnosed, and strongly associated with depression, anxiety, sleep disturbance and sexual dysfunction.

Mechanisms. Nociceptive input from inflamed or scarred organs, peripheral and central sensitisation, viscerosomatic and viscerovisceral convergence (so one organ's disease worsens symptoms in another), pelvic floor hypertonicity, nerve entrapment, and psychological and social amplification.

Classification:

• By source: gynaecological, urological, gastrointestinal, musculoskeletal and neurological, psychological.
• By pattern: cyclical or non cyclical, constant or intermittent.
• By diagnosis: with an identified cause, or chronic primary pelvic pain syndrome when no cause explains symptoms.

Key distinctions. Pain reproduced by raising the head or legs while palpating a fixed tender point suggests abdominal wall pain. Pain with bladder filling relieved by voiding suggests bladder pain syndrome. Pain related to bowel habit suggests irritable bowel syndrome. Cyclical pain with deep dyspareunia suggests endometriosis or adenomyosis.

History

• Pain: site, quality (burning, cramping, stabbing, aching), radiation, onset, duration, triggers (intercourse, posture, exercise, bladder or bowel filling), relation to menses, severity score from 0 to 10, function.
• Gynaecological: menstrual pattern, dysmenorrhoea, dyspareunia (superficial or deep), infertility, previous pelvic inflammatory disease, sexually transmitted infection, contraception (intrauterine device), endometriosis in relatives.
• Urological: urgency, frequency, nocturia, bladder pain relieved by voiding, dysuria, haematuria, recurrent urinary tract infection.
• Bowel: constipation, diarrhoea, bloating, pain relieved by defaecation, rectal bleeding, weight loss.
• Musculoskeletal and neurological: back pain, hip pain, sitting pain, pain after hernia repair or pelvic surgery, burning or numbness in dermatomes.
• Surgical and obstetric: caesarean section, hysterectomy, mesh, difficult delivery, perineal tears.
• Previous investigation and treatment, and response to each.
• Psychological: depression, anxiety, post traumatic stress, abuse (ask with permission and privately), sleep, opioid and other drug use, relationship and employment effects.
• Endemic infection: genital tuberculosis, schistosomiasis.

Examination

• Vital signs, BMI, abdomen for masses, hernias, scars, and focal tenderness.
• Carnett sign: pain on palpation that persists or worsens when the abdominal muscles are tensed (head raise or straight leg raise) suggests abdominal wall pain.
• Back, hips, sacroiliac joints, and coccyx.
• Pelvic examination with consent and chaperone: vulva and vestibule (cotton swab test), speculum, single finger examination of pelvic floor muscles (levator ani, obturator internus, piriformis), uterus size, mobility and tenderness, adnexa, uterosacral nodularity, anterior vaginal wall and urethra tenderness, pudendal nerve at the ischial spine.
• Rectal examination when bowel symptoms are present.
• Neurological examination of the lower limbs and perineal sensation.

Red flags

• Postmenopausal bleeding, new pelvic mass, ascites, early satiety or bloating (ovarian cancer).
• Weight loss, rectal bleeding, anaemia or change in bowel habit (colorectal cancer, inflammatory bowel disease).
• Haematuria (bladder cancer, stone).
• Fever or offensive discharge (pelvic inflammatory disease, abscess).
• Cauda equina features: saddle numbness, new urinary retention or incontinence, bilateral leg weakness.
• Pregnancy with pain.
• Cervical or vaginal lesion, or abnormal screening.
• Recent surgery with pain and fever (collection, bowel injury, retained swab).

Special groups. Women with a history of abuse need trauma informed examination. Women who have had a hysterectomy: consider adhesions, ovarian remnant, bowel and urological causes. Older women: malignancy, prolapse and bowel disease. Endemic regions: genital tuberculosis and schistosomiasis.

Organised by source. Each cause is common unless marked serious or uncommon. Gynaecological

• Endometriosis (peritoneal, ovarian, deep infiltrating).
• Adenomyosis.
• Chronic pelvic inflammatory disease, hydrosalpinx, tubo ovarian remnants.
• Pelvic adhesions after surgery or infection.
• Pelvic congestion syndrome (dull ache worse standing and late in the day, pelvic varices).
• Uterine fibroids and large ovarian cysts.
• Ovarian remnant syndrome and residual ovary syndrome (after oophorectomy or hysterectomy).
• Chronic endometritis and retained intrauterine device.
• Pelvic organ prolapse.
• Genital tuberculosis and genital schistosomiasis in endemic regions.
• Cervical stenosis.
• Serious: ovarian cancer, uterine, cervical and vaginal cancer, pelvic radiation injury.

Urological

• Interstitial cystitis (bladder pain syndrome).
• Recurrent urinary tract infection and urethral syndrome.
• Urethral diverticulum.
• Bladder stone, bladder cancer (serious), ureteric stone or stricture.
• Urethral caruncle.

Gastrointestinal

• Irritable bowel syndrome, chronic constipation.
• Inflammatory bowel disease, coeliac disease.
• Diverticular disease, chronic appendicitis.
• Proctalgia fugax and levator ani syndrome.
• Colorectal cancer (serious), anorectal disease.

Musculoskeletal and neurological

• Pelvic floor myalgia and hypertonicity, piriformis syndrome.
• Anterior cutaneous nerve entrapment syndrome and abdominal wall trigger points.
• Pudendal neuralgia, ilioinguinal, iliohypogastric and genitofemoral neuralgia (often after surgery or hernia repair).
• Hernia (inguinal, femoral, incisional, obturator).
• Hip pathology (femoroacetabular impingement, arthritis), sacroiliac joint dysfunction, coccydynia, lumbar radiculopathy.
• Symphysis pubis dysfunction (postpartum).
• Serious: spinal cord or cauda equina compression, sacral tumours.

Psychological and central

• Chronic primary pelvic pain syndrome (no organ cause).
• Depression, anxiety, post traumatic stress disorder, sexual abuse sequelae, somatic symptom disorder.
• Opioid induced hyperalgesia and narcotic bowel syndrome.

Stepwise reasoning

1. Exclude alarm features and pregnancy, and test for infection.
2. Examine the abdominal wall, pelvic floor, bladder, bowel and gynaecological organs systematically.
3. Order first line tests and transvaginal ultrasound, and treat the findings.
4. Escalate to MRI, endoscopy or laparoscopy only for defined questions or treatment failure.
5. Assess psychosocial factors and function in every patient.

First line tests

• Urine pregnancy test.
• Urine dipstick, microscopy and culture.
• Nucleic acid amplification tests for chlamydia, gonorrhoea, Trichomonas vaginalis and Mycoplasma genitalium; vaginal swab for pH and microscopy.
• Full blood count, C reactive protein, ferritin, urea, creatinine, liver function tests, HbA1c, thyroid stimulating hormone.
• Coeliac serology and faecal calprotectin for bowel symptoms.
• Transvaginal ultrasound: endometrioma, adenomyosis, fibroids, hydrosalpinx, adnexal mass, pelvic varices (diameter over 5 mm with slow flow), and the sliding sign.
• Cervical screening if due.

Targeted tests

• CA 125 only when a pelvic mass is present, interpreted with menopausal status and imaging.
• MRI pelvis for suspected deep endometriosis, adenomyosis, urethral diverticulum or complex masses; MRI lumbosacral spine for neurological features.
• Pelvic venography or CT or MR venography for suspected pelvic congestion syndrome.
• Cystoscopy with hydrodistension and biopsy for bladder pain syndrome or haematuria.
• Colonoscopy for rectal bleeding, anaemia, weight loss, change in bowel habit with age over 40, or positive faecal markers.
• Diagnostic laparoscopy for persistent pain with negative imaging when endometriosis, adhesions or pelvic congestion remain likely and treatment has failed, with excision of any disease found.
• Diagnostic local anaesthetic injections: abdominal wall trigger point injection, pudendal or ilioinguinal nerve block, with response supporting the diagnosis.
• Genital tuberculosis: endometrial biopsy or menstrual blood for culture and nucleic acid amplification, hysterosalpingography (with caution), chest radiograph, and laparoscopy when needed. Genital schistosomiasis: urine microscopy for eggs, biopsy and serology.
• Hip and sacroiliac imaging, and bone density when indicated.

Limitations. Laparoscopic findings correlate poorly with pain, and a normal laparoscopy does not exclude pain from other sources. Repeated surgery increases adhesions and can worsen pain. Ultrasound and MRI can miss superficial peritoneal disease. Many women have more than one cause.

Immediate steps. Treat sepsis, ectopic pregnancy and surgical emergencies. Refer suspected cancer urgently. Explain that chronic pain is real, often has several contributors, and that the plan is to reduce pain and improve function.

General measures. Agree goals of function (work, sleep, sexual activity, exercise). Provide a pain diary, sleep advice, graded activity, and pacing. Treat constipation, depression, anxiety and sleep problems. Avoid long term opioids; limit short courses and avoid in chronic pain unless specialist directed.

Analgesia

• Paracetamol 1 g orally every 4 to 6 hours, maximum 4 g daily (3 g daily with chronic alcohol use, malnutrition or hepatic impairment; 15 mg/kg each dose under 50 kg).
• Ibuprofen 400 mg orally every 6 to 8 hours with food, maximum 2.4 g daily; or naproxen 500 mg orally twice daily with food, maximum 1 g daily; avoid in peptic ulcer, renal impairment, heart failure and NSAID sensitive asthma; limit duration.
• Neuropathic pain or central sensitisation:
  • Amitriptyline 10 mg orally at night, increased by 10 mg every 1 to 2 weeks to 50 to 75 mg at night; maximum 100 mg. ECG when over 50 years or with heart disease. Avoid with MAO inhibitors; caution with SSRIs and tramadol (serotonin syndrome), epilepsy, glaucoma and urinary retention.
  • Gabapentin 300 mg orally at night, increased by 300 mg every 3 to 7 days to 900 to 1800 mg daily in 3 doses; maximum 3.6 g daily. Reduce for creatinine clearance under 60 mL/min. Monitor sedation, dizziness and misuse. Avoid in pregnancy.
  • Duloxetine 30 mg orally daily for 1 to 2 weeks, then 60 mg daily; maximum 120 mg daily. Avoid with MAO inhibitors, uncontrolled hypertension, severe renal impairment (creatinine clearance under 30 mL/min) and hepatic impairment. Monitor blood pressure and sodium.

Hormonal treatment for endometriosis, adenomyosis and cyclical pain

• Combined oral contraceptive with 30 to 35 microgram ethinylestradiol taken continuously or in 3 pack cycles, with the usual contraindications (migraine with aura, previous thromboembolism, smoking over age 35, uncontrolled hypertension).
• Options:
  • Dienogest 2 mg orally once daily continuously (maximum 2 mg daily).
  • Norethisterone acetate 5 mg orally once daily increased by 2.5 mg every 2 weeks to a maximum of 15 mg daily.
  • Levonorgestrel 52 mg intrauterine system.
  • Depot medroxyprogesterone acetate 150 mg intramuscularly every 12 weeks (bone density loss).
• Second line: leuprorelin 3.75 mg intramuscularly every 4 weeks for up to 6 months with add back norethisterone acetate 5 mg daily, with bone density monitoring.
• Laparoscopic excision of endometriosis and adhesiolysis for failure of medical treatment, endometrioma or deep disease; hysterectomy with oophorectomy only after other options in women who have completed families.

Cause specific treatment

• Chronic pelvic inflammatory disease: ceftriaxone 1 g intramuscularly once, doxycycline 100 mg orally twice daily for 14 days and metronidazole 400 mg orally twice daily for 14 days; treat partners.
• Pelvic congestion syndrome: medroxyprogesterone acetate 30 mg orally daily has been used with limited evidence; ovarian vein embolisation by interventional radiology for confirmed disease.
• Bladder pain syndrome: urology referral; amitriptyline 10 mg orally at night increased by 10 mg every 1 to 2 weeks to 50 to 75 mg, bladder training, and intravesical therapy by specialists.
• Irritable bowel syndrome: mebeverine 135 mg orally three times daily 20 minutes before meals (maximum 405 mg daily), or peppermint oil 0.2 to 0.4 mL orally three times daily before meals, dietary advice and soluble fibre. Constipation: macrogol 3350 with electrolytes 1 to 3 sachets daily dissolved in water, adjusted to stool.
• Abdominal wall pain and trigger points: lidocaine 1% 2 to 5 mL injected into each tender point (maximum 200 mg of plain lidocaine, 3 mg/kg), with or without a corticosteroid; repeat at intervals directed by response; neurectomy for refractory entrapment.
• Pudendal neuralgia: pudendal nerve block with bupivacaine 0.25% (maximum 2 mg/kg) with or without a corticosteroid. Amitriptyline 10 mg orally at night increased by 10 mg every 1 to 2 weeks to 50 to 75 mg (maximum 100 mg), or gabapentin 300 mg orally at night increased to 900 to 1800 mg daily in 3 doses. Decompression for refractory cases.
• Pelvic floor myalgia: pelvic floor physiotherapy with biofeedback, relaxation techniques, vaginal dilators and trigger point release; botulinum toxin has limited evidence.
• Genital tuberculosis: isoniazid 5 mg/kg (maximum 300 mg) daily, rifampicin 10 mg/kg (maximum 600 mg) daily, pyrazinamide 25 mg/kg daily and ethambutol 15 mg/kg daily for 2 months, then isoniazid and rifampicin daily for 4 months. Add pyridoxine 10 mg daily. Check liver function at baseline and during treatment. Reduce ethambutol in renal impairment. Screen for HIV. Specialist care.
• Genital schistosomiasis: praziquantel 40 mg/kg orally as a single dose, which may be split into two doses on the same day.
• Ovarian remnant syndrome and adhesions: gynaecological surgery after imaging.
• Prolapse: pelvic floor physiotherapy, pessary or surgery.

Psychological and behavioural treatment. Cognitive behavioural therapy, acceptance based therapy, sex therapy, and trauma focused therapy where indicated. Multidisciplinary pain clinic care for refractory pain.

Monitoring. Review at 4 to 6 weeks and 3 months, then every 3 to 6 months. Track pain scores from 0 to 10, function, sleep, mood, side effects, and bone density with depot medroxyprogesterone acetate or gonadotropin releasing hormone agonist use. Stop a drug that has not helped after an adequate course (6 to 8 weeks at the target dose for neuropathic agents).

Referral and escalation. Refer urgently within 2 weeks for suspected cancer. Refer to gynaecology for suspected endometriosis, adenomyosis, adhesions, pelvic congestion or failure of 3 months of first line treatment. Refer to urology, colorectal surgery, pain medicine, pelvic floor physiotherapy and psychology as the findings direct. Refer to infectious disease for tuberculosis.

Admission criteria. Sepsis, tubo ovarian abscess, suspected torsion, intractable pain needing parenteral analgesia, and surgical emergencies.

Discharge and follow up. Outpatient, multidisciplinary care with a named clinician and written plan. Safety netting. Return for fever, vomiting, bleeding, weight loss, new urinary or bowel symptoms, new neurological symptoms, or sudden severe pain.