Chronic Pelvic Pain
Differential Diagnosis
Common Diagnoses
- Endometriosis
- Chronic Pelvic Inflammatory Disease
- Pelvic Congestion
- Irritable Bowel Syndrome
- Physiological (Mittelschmerz, Primary Dysmenorrhoea)
Occasional Diagnoses
- Recurrent UTI
- Musculoskeletal Pain (Back Pain, Pubic Symphysis Pain)
- Uterovaginal Prolapse
- Chronic Interstitial Cystitis
- IUCD
- Adhesions (from Previous Surgery)
- Fibroids
- Ovarian Cyst
Rare Diagnoses
- Malignant Tumours (Ovary, Cervix, Bowel)
- Diverticulitis
- Lower Colonic Cancer
- Inflammatory Bowel Disease
- Subacute Bowel Obstruction
Ready Reckoner
Key distinguishing features of the most common diagnoses
| Endometriosis | PID | Pelvic Congestion | IBS | Physiological | |
|---|---|---|---|---|---|
| Worse Around Period | Yes | Possible | Yes | Possible | Possible |
| Heavy Periods | Yes | Yes | Yes | No | Possible |
| Altered Bowel Habit | No | No | No | Yes | No |
| Subfertility | Possible | Yes | No | No | No |
| Ovarian Tenderness | Possible | Possible | Yes | No | No |
Possible Investigations
Likely:MSU, CA-125.
Possible: Laparoscopy, ultrasound, HVS and cervical swab.
Small Print: FBC, ESR/CRP, bowel and back imaging.
- MSU detects UTI. Red cells alone may be present in interstitial cystitis.
- CA-125 – especially in women aged 50 or more to help rule out carcinoma of the ovary
- FBC, ESR/CRP: WCC, ESR/CRP may be raised during exacerbation of chronic PID.
- HVS and cervical swab for Chlamydia may help in determining the infective agent in PID
- Ultrasound is helpful if there is a palpable mass or if CA-125 is elevated
- Laparoscopy is the investigation of choice for diagnosing PID, endometriosis and pelvic congestion.
- Further investigations, such as bowel and back imaging, might be undertaken by the specialist after referral.
Top Tips
- A ‘forgotten’ coil can cause cyclical pelvic pain
- If the pain links with periods, establish whether it is primary or secondary dysmenorrhoea – the latter is far more likely to have a pathological cause.
- In some cases the diagnosis will remain obscure. Avoid colluding with obviously erroneous diagnoses and try to adopt a constructive approach without over-investigating the patient.
- Don’t overlook non-gynaecological causes.
- Bloating is a very common gynaecological symptom, but is characteristic of IBS. A trial of antispasmodics may aid diagnosis.
- Misdiagnosis of PID without reliable evidence will delay the real diagnosis and lead to repeated courses of unnecessary antibiotics.
Red Flags
- Women over 35 at first presentation and those with a mass should be referred for a gynaecological opinion.
- Ovarian cancer nearly always presents late. Have a low threshold for investigation.
- Even if endometriosis is confirmed at laparoscopy it may not be the cause of a women's pelvic pain. Remember that many women with similar findings are asymptomatic. Discuss this openly with the patient – this will help manage expectations if she does not improve with anti-endometriotic treatment.