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

How common is acute pelvic pain?

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

Causes of acute pelvic pain (aetiology)

Common causes include pelvic inflammatory disease (PID), 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 (rarely) uterine rupture.

• Gynaecological: ovulation (mid-cycle, may be severe pain), dysmenorrhoea, PID, rupture or torsion of ovarian cyst, degenerative changes in a fibroid; the possibility of a pelvic tumour or pelvic vein thrombosis should also be considered.

• Other causes: these include appendicitis, irritable bowel syndrome (IBS), adhesions, prostatitis, strangulated hernia and interstitial cystitis.

Investigations

• Urinalysis, midstream specimen of urine (MSU) - depending on the history, it may also be appropriate to send urine or a swab for sexually transmitted infections such as chlamydia and gonorrhoea.

• High vaginal swab (HVS) for bacteria and and appropriate tests for chlamydia and gonorrhoea.¹

• Pregnancy test.

• Blood tests as appropriate - for example, a FBC if the pain is associated with heavy periods, inflammatory markers if an acute infection is suspected.

• Ultrasound,if miscarriage or ectopic pregnancy is suspected - an ultrasound will often not see an ectopic pregnancy, but an empty uterus in the presence of a positive pregnancy test is strongly suggestive of an ectopic pregnancy. This would usually be arranged by your local early pregnancy assessment unit, in order for it to be done swiftly.

• Laparoscopy.

Management of acute pelvic pain

• Management is based on identifying and treating the cause.

• Empirical use of antibiotics and analgesia without a clear diagnosis should be avoided.

• Referral is required if the diagnosis cannot be established and if there is no response to treatment in primary care. If the patient is acutely unwell then immediate referral, rather than investigation or management in primary care, may be appropriate.

• Urgent admission is necessary if there is a possibility of urgent treatment being required - eg, ectopic pregnancy, appendicitis or if the patient is haemodynamically unstable.

Chronic pelvic pain

How common is chronic pelvic pain?

Chronic pelvic pain is much more common in women than in men. It may occur in as many as 1 in 6 adult women.²

• Chronic pelvic pain is defined as:

  • Intermittent or constant pain in the lower abdomen or pelvis in women.

  • Lasting for at least six months.

  • Not occurring exclusively with menstruation or sexual intercourse.

  • Not being associated with pregnancy.

• Chronic pelvic pain is a symptom, not a diagnosis.

• The prevalence of chronic pelvic pain in general practice has been estimated to range between 5.7% and 26.6%.³

Causes of chronic pelvic pain (aetiology)

• The aetiology of chronic pelvic pain is still not well understood.

• There is often more than one cause of the pain.

• The pain may persist long after the original tissue injury has healed.

• Psychological, social and physical factors are all important in the aetiology.

• Persistence of pain may lead to changes within the central nervous system, which magnify the original signal.

• Sensation and perception of pain can be influenced by previous experiences.

• Nerve damage following surgery, trauma, inflammation, fibrosis or infection may play a part in pain perception.

Possible causes of chronic pelvic pain include:

• Endometriosis:

  • Pain usually varies during menstrual cycle but as time goes on it may be present all month.

  • Can be associated with dysmenorrhoea and dyspareunia, as well as other cyclical changes such as cyclical epistaxis or dyschezia (pain on defecation).

• Adhesions:

  • May be caused by previous surgery, endometriosis, previous infection.

  • Some adhesions are asymptomatic.

• IBS.

• Interstitial cystitis.

• Musculoskeletal problems.

• Pelvic organ prolapse.

• Nerve entrapment:

  • This can occur in scar tissue or fascia.

• Psychological and social issues:

  • Depression and sleep disorders are common.

  • Some studies have suggested that women with chronic pelvic pain are more likely to have experienced physical or sexual abuse as children.^{4 5 6}

• Other causes in men include epididymo-orchitis and testicular tumours.

• Chronic pain in the region of the prostate was previously called chronic prostatitis; however, there is a proven bacterial infection in only 10% of these cases. The remaining 90% should now be classified as prostate pain syndrome (PPS), based on the fact that there is no proven infection or other obvious pathology.⁷

Presentation

• Initial history should include questions about the pattern of the pain and its association with other problems. These may include bladder and bowel symptoms and the effect of movement and posture on the pain.

• Questions should be asked regarding psychological and social issues.

• Although many symptom complexes (eg, IBS) 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 - eg, endometriosis.

• Suggested red flag symptoms and signs:²
  

  • Bleeding per rectum.

  • New bowel symptoms in patients over 50 years old (see 'Investigations', below).

  • New pain after the menopause.

  • Pelvic mass.

  • Suicidal ideation.

  • Excessive weight loss.

  • Irregular vaginal bleeding in patients over 40 years old.

  • Postcoital bleeding.

NB: women with chronic pelvic pain often present without obvious cause on history, investigations or physical examination.⁸

Investigations

• Samples to screen for infection (particularly chlamydia and gonorrhoea) should be considered in all those who are, or have been, sexually active.

• Ideally, all sexually active women below the age of 25 years who are being examined should be offered opportunistic screening for chlamydia - this is also available to them via the national screening programme.⁹

• Blood tests such as FBC and CRP may be useful for some women.

• Ca125 measurement is appropriate if symptoms suggesting ovarian cancer are experienced. A new diagnosis of IBS in a woman aged over 50 years is suspicious.¹⁰

• Urinalysis and send MSU.

• Transvaginal scanning (TVS) using ultrasound is an appropriate investigation to screen for and assess adnexal masses.

• TVS and magnetic resonance imaging (MRI) are useful tests to diagnose adenomyosis. The role of MRI in diagnosing small deposits of endometriosis is uncertain and it is not a test that should be used in primary care for the diagnosis of endometriosis.

• Diagnostic laparoscopy has been regarded in the past as the gold standard in the diagnosis of chronic pelvic pain, but the RCOG guidance comments that it may be better seen as a second line of investigation if other therapeutic interventions fail.²

• Further urological investigations (eg, cystourethroscopy) and/or bowel investigations (eg, barium enema) may be required.

Management of pelvic pain

Management is focused on identifying and treating the cause but the psychosocial causes and effects of chronic pelvic pain should also be considered. The management of chronic pelvic pain is challenging, as despite interventions involving surgery, many women remain in pain without a firm gynaecological diagnosis.¹¹

• The aim of treatment should be to develop a partnership between clinician and patient to plan a management programme.

• A multidisciplinary approach to assessment and treatment with a focus on improving emotional, physical and social functioning instead of focusing strictly on pain reduction should be undertaken.

• The woman should be given adequate time to tell her story. A symptom diary may be useful.

• 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 a gastroenterologist, urologist, colorectal surgeon, or genitourinary specialist may be appropriate.

• For some patients, the involvement of a physiotherapist, psychologist, social prescribing link worker 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 three to six months before having a diagnostic laparoscopy.² The levonorgestrel-releasing intrauterine system could be considered - there are now various brands of these on the market in the UK. GnRH agonists are not usually started in primary care.

• Division of fine adhesions has not been proven to be beneficial, but division of dense adhesions is associated with pain relief.²

• Appropriate analgesia to control pain should be given, even if no other therapeutic manoeuvres are yet to be initiated. If pain is not adequately controlled, there may be a need to refer the patient to a pain management team or a specialist pelvic pain clinic.However, we should bear in mind the recent change in focus away from the use of opiates, antiepileptics, antipsychotics and benzodiazepines for the use of chronic pain.¹²

• For men with pelvic pain syndrome, the following are recommended:⁷

  • Alpha-blockers in those with symptoms for less than one year.

  • Antibiotics (quinolones or tetracyclines) for at least six weeks for those with symptoms for less than one year.

  • Non-steroidal anti-inflammatory drugs (NSAIDs) may be effective.

  • Electro-acupuncture or perineal extracorporeal shock wave therapy may be considered for some men.

  • Phytotherapy with herbal medication.

  • Physical therapies such as acupuncture, and psychological therapies.