Pelvic Pain

Pelvic pain is both a common presentation in primary care and one of the most common reasons for referral to a gynaecologist. Pelvic pain may be either acute or chronic.

Acute pelvic pain is much more common in women than men. Most women experience mild pelvic pain at some time due to periods, ovulation or sexual intercourse. In its severest form, it is the most common reason for urgent laparoscopic examination in the UK.

Causes

Common causes include pelvic inflammatory disease, urinary tract infection (UTI), miscarriage, ectopic pregnancy and torsion or rupture of ovarian cysts.

• Pregnancy related: miscarriage, ectopic pregnancy, rupture of corpus luteum cyst; causes in later pregnancy include premature labour, placental abruption and uterine rupture.
• Gynaecological: ovulation (mid-cycle, may be severe pain), dysmenorrhoea, pelvic inflammatory disease, rupture or torsion of ovarian cyst, degenerative changes in a fibroid; must also consider possibility of a pelvic tumour or pelvic vein thrombosis.
• Other causes include appendicitis, irritable bowel syndrome, UTI, adhesions, strangulated hernia, prostatitis in men.

Investigations

• Urinalysis, MSU.
• HVS for bacteria and endocervical swab if purulent discharge present.
• Pregnancy test: positive in ectopic and miscarriage.
• Full blood count: infection.
• Urgent ultrasound if miscarriage or ectopic pregnancy is suspected.
• Laparoscopy may be required.

Management

• Management is based on identifying and treating the cause. Empirical use of antibiotics and analgesia without a clear diagnosis must be avoided.
• Referral is required if the diagnosis cannot be established (especially if there is a possibility of urgent treatment required, e.g. ectopic, appendicitis), patient is haemodynamically unstable or if there is no response to treatment in primary care.

Chronic pelvic pain is much more common in women than men.

• Chronic pelvic pain is defined as non-malignant pain perceived in structures related to the pelvis of either men or women that has been continuous or recurrent for at least 6 months. It is a symptom, not a diagnosis.¹
• Chronic pelvic pain presents in primary care as frequently as migraine or low back pain.²
• Often investigations, including laparoscopy, reveal no obvious cause for the pain.³

Causes

• Endometriosis, adenomyosis: cardinal symptoms are dysmenorrhoea, dyspareunia and chronic pelvic pain but symptoms alone are a poor predictor of diagnosing endometriosis. The combination of clinical examination and transvaginal ultrasound accurately identifies ovarian endometriosis but not peritoneal disease.²
• Pelvic venous congestion: has also been proposed as a cause of pelvic pain with menstrual exacerbation.
• Fibroids
• Pelvic inflammatory disease
• Adhesions: may be a cause of pain but may be asymptomatic.
• Gastrointestinal, e.g. irritable bowel syndrome, diverticular disease.
• Urological, e.g. interstitial cystitis, chronic urethritis, urinary tract calculi
• Musculoskeletal pain, e.g. low back pain, fibromyalgia.
• Post-herpetic neuralgia
• Psychological and social issues: commonly occur in association with chronic pelvic pain and may be important in resolving symptoms

Other causes in men include epididymo-orchitis, prostatitis and testicular tumours.¹

• Initial history should include questions about the pattern of the pain and its association with other
  problems, such as psychological, bladder and bowel symptoms, and the effect of movement and posture on the pain.
• Symptoms alone may be used to diagnose irritable bowel syndrome positively in this age group
• Although many symptom complexes, e.g. irritable bowel syndrome, and pain perception itself may vary a little with the menstrual cycle (50% of women experience a worsening of their symptoms in association with their period), strikingly cyclical pain is usually gynaecological in nature.
• Suggested red flag symptoms and signs:²
  • Bleeding per rectum
  • New bowel symptoms over 50
  • New pain after the menopause
  • Pelvic mass
  • Suicidal ideation
  • Excessive weight loss
  • Irregular vaginal bleeding over 40
  • Post coital bleeding

• Samples to screen for infection, particularly chlamydia and gonorrhoea, should be taken if there is any suspicion of pelvic inflammatory disease. Ideally, all sexually active women below the age of 25 years who are being examined should be offered opportunistic screening for chlamydia.
• Full blood count, CRP.
• Urinalysis and send MSU.
• Transvaginal ultrasound scanning is an appropriate investigation to screen for and assess adnexal masses.
• Transvaginal scanning and magnetic resonance imaging (MRI) are useful tests to diagnose adenomyosis. The role of MRI in diagnosing small deposits of endometriosis is uncertain.
• Diagnostic laparoscopy has been regarded in the past as the gold standard in the diagnosis of chronic pelvic pain. It may be better seen as a second line of investigation if other therapeutic interventions fail.
• Further urological investigations, e.g. cystourethroscopy, and/or bowel investigations, e.g. barium enema, may be required.

Management is focused on identifying and treating the cause but the psychosocial causes and effects of chronic pelvic pain should also be considered.²

• The multifactorial nature of chronic pelvic pain should be discussed and explored with the patient from the start. The aim should be to develop a partnership between clinician and patient to plan a management programme.
• Appropriate management of any specific underlying disorder.
• Many women with chronic pelvic pain can be managed in primary care. Referral should be considered when the pain has not been explained to the woman's satisfaction or when pain is inadequately controlled.
• If the history suggests a non-gynaecological component to the pain, referral to gastroenterologist, urologist, genitourinary, physiotherapist, psychologist or psychosexual counsellor should be considered.
• Women with cyclical pain should be offered a therapeutic trial using the combined oral contraceptive
  pill or a gonadotrophin-releasing hormone (GNRH) agonist for a period of 3 months before having a
  diagnostic laparoscopy. The levonorgestrel-releasing intrauterine system (Mirena® coil) could be considered.
• Appropriate analgesia to control pain, even if no other therapeutic manoeuvres are yet to be initiated. If pain is not adequately controlled, may need refer to a pain management team or a specialist pelvic pain clinic.