Endometriosis: diagnosis and management

1Clinical Context, Definition, and Presentation

An overview of endometriosis pathophysiology, typical symptoms, and the clinical challenges associated with delayed diagnosis.

• DefinitionEndometriosis is defined as the growth of endometrial-like tissue (the womb lining) outside the uterus.
  • It is an oestrogen-dependent, hormone-mediated inflammatory condition associated with menstruation.
  • It primarily affects individuals during their reproductive years, though it can sometimes persist beyond.
• SymptomsCommon clinical presentations of endometriosis include:
  • Pelvic pain (frequent, chronic, and/or severe)
  • Dysmenorrhoea (painful periods affecting daily activities and quality of life)
  • Deep pain during or after sexual intercourse (dyspareunia)
  • Period-related or cyclical gastrointestinal symptoms (especially painful bowel movements)
  • Period-related or cyclical urinary symptoms (especially haematuria or dysuria)
  • Subfertility, tiredness, and fatigue
  • Significant physical, sexual, psychological, and social impact leading to reduced quality of life.
• CautionAsymptomatic presentation is possible; endometriosis may be discovered incidentally during other procedures.
  • It remains unclear whether asymptomatic endometriosis is always progressive, stable, or improves over time.
• Diagnostic DelayDelays of 4 to 10 years commonly occur between the first presentation of symptoms and definitive diagnosis.
  • Contributing factors: Healthcare professionals failing to recognize symptoms, and patients normalizing pelvic pain.
  • Consequences: Increased personal suffering, prolonged ill health, and progression to a disease state that is more difficult to treat.

2Organisation of Care and Service Delivery

Establish a managed clinical network for suspected or confirmed endometriosis.

• Delays in diagnosis and treatment can lead to disease progression and severely affect quality of life.

3Endometriosis Information and Support

Guidelines on addressing the long-term physical, psychological, and social impacts of endometriosis through individualized support and comprehensive patient education.

• Recognize endometriosis as a long-term condition with multidimensional impacts.
  • Can cause significant physical, sexual, psychological, and social distress.
  • Patients often present with complex needs requiring long-term, structured support.
• Conduct an individualized assessment of information and support needs.
  • Factors to assess: individual circumstances, symptoms, priorities, and desire for fertility.
  • Impact areas: daily living, work, study, cultural background, physical, psychosexual, and emotional needs.
• Provide comprehensive, stage-appropriate information and support resources covering key educational domains.
  • Involve partners and family members in discussions if the patient agrees.

4Symptoms and Signs (Initial Assessment)

• Suspect endometriosis in women and people (including young women aged 17 and under) presenting with 1 or more key clinical indicators:
  • Chronic pelvic pain
  • Period-related pain (dysmenorrhoea) affecting daily activities and quality of life
  • Deep pain during or after sexual intercourse (dyspareunia)
  • Period-related or cyclical gastrointestinal symptoms (especially painful bowel movements)
  • Period-related or cyclical urinary symptoms (especially haematuria or dysuria)
  • Infertility associated with 1 or more of the above symptoms
• Family HistoryA positive family history of endometriosis must be factored into the clinical assessment.
  • There is a significantly increased likelihood of endometriosis if a first-degree relative is affected.
  • Identifying this history should prompt earlier diagnostic investigations (e.g., ultrasound) to reduce diagnostic delay.
• Diversity and Pain AssessmentClinicians must actively take diversity into account when assessing pain symptoms.
  • Advise keeping a pain and symptom diary to aid clinical discussions.
  • Acknowledge that pain expression is unique and may vary due to cultural background, socioeconomic status, and neurodiverse conditions.
  • Ensure pain symptoms are believed, addressing evidence that many ethnic minority groups report that their pain symptoms are not believed or taken seriously.
• Physical Examination Protocols
  • Offer an abdominal and pelvic (internal vaginal) examination to identify: abdominal masses, reduced organ mobility and enlargement, tender nodularity in the posterior vaginal fornix, or visible vaginal endometriotic lesions.
  • Offer an abdominal examination alone to exclude masses if a pelvic (internal vaginal) examination is declined or unsuitable.

5Diagnostic and Referral Pathways

• Parallel PathwayConduct investigations (such as ultrasound) and referrals in parallel with initial pharmacological treatment.
  • Initial pharmacological treatment, non-specialist ultrasound, and gynaecology referral do not need to occur sequentially to avoid unnecessary delays.
• UltrasoundOffer a transvaginal ultrasound (TVUS) scan to all patients with suspected endometriosis, even if pelvic or abdominal examination is normal.
  • Use TVUS to identify ovarian endometriomas, deep endometriosis (including bowel, bladder, or ureter involvement), and other pelvic pathologies.
  • Consider a transabdominal ultrasound of the pelvis if TVUS is declined or clinically unsuitable.
  • Caution: Do NOT exclude endometriosis solely because abdominal/pelvic examinations or ultrasound scans are normal.
• CA125Do NOT use serum CA125 to diagnose endometriosis.
  • Evidence remains insufficient to support CA125 as a suitable diagnostic tool.
• MRIConsider a specialist TVUS or pelvic MRI scan to diagnose deep endometriosis and assess its anatomical extent.
• LaparoscopyConsider laparoscopy to diagnose endometriosis even if ultrasound or MRI scans are normal.
  • For suspected deep endometriosis, consider a specialist pelvic ultrasound or MRI scan before performing an operative laparoscopy.
  • Laparoscopy requirements: Must be performed by a gynaecologist trained in laparoscopic surgery for endometriosis, involving systematic pelvic inspection and detailed recording of findings (including normal/abnormal areas and intra-operative imaging).
  • Biopsy considerations: Consider taking a biopsy of suspected lesions to confirm diagnosis (note: negative histology does not exclude endometriosis) or to exclude malignancy if an endometrioma is treated but not excised.
  • If a systematic laparoscopy is normal, explain that endometriosis is unlikely and offer alternative symptom management.

6Pharmacological Treatment

• Initial Analgesic Management
  • Discuss benefits and risks of analgesics, accounting for comorbidities and preferences.
  • Consider a short trial (e.g., 3 months) of paracetamol or an NSAID (alone or in combination) as first-line management.
  • If first-line trial fails, consider other pain management options and referral.
• Hormonal Treatments
  • Counsel patients that hormonal treatment reduces pain and has no permanent negative effect on subsequent fertility.
  • Offer hormonal treatment (e.g., combined oral contraceptive pill [COCP] or a progestogen) to patients with suspected, confirmed, or recurrent endometriosis.
• GnRH AntagonistsGonadotrophin-Releasing Hormone (GnRH) Antagonists
  • Recommended options for treating symptoms in adults of reproductive age after medical or surgical treatment:
  • Linzagolix with hormonal add-back therapy (TA1067, June 2025)
  • Relugolix–estradiol–norethisterone (TA1057, April 2025)

7Surgical Management

Laparoscopic surgical strategies, pre-operative preparation, post-operative medical therapies, and considerations for hysterectomy.

• Pre-operative Consultation
  • Ask patients about symptoms, preferences, and priorities regarding pain and fertility to guide surgical decision-making.
  • Discuss: laparoscopy procedure, potential for immediate surgical treatment (requires prior consent), symptom impact, risks/benefits, risk of recurrence/further surgery, and potential for planned staged surgery for deep endometriosis.
• Surgical Approach and Intra-operative Decisions
  • Perform surgery laparoscopically unless contraindicated, and record findings with intra-operative imaging.
  • During diagnostic laparoscopy, consider immediate laparoscopic treatment of peritoneal endometriosis (not involving bowel/bladder/ureter) and uncomplicated ovarian endometriomas.
  • Pre-operative medical adjunct: Consider 3 months of GnRH agonists before surgery for deep endometriosis involving the bowel, bladder, or ureter.
  • Excision vs. Ablation: Consider excision rather than ablation to treat endometriomas, taking into account the patient's desire for fertility and ovarian reserve.
• Post-operative Medical Management
  • Consider post-operative hormonal treatment (e.g., combined oral contraceptive pill) after laparoscopic excision or ablation to prolong the benefits of surgery and manage symptoms.
  • Caution: Some hormonal treatments may be used off-label for this indication.
• Hysterectomy in Combination with Surgical Management
  • If hysterectomy is indicated (e.g., due to co-existing adenomyosis or refractory heavy menstrual bleeding), excise all visible endometriotic lesions at the time of hysterectomy.
  • Perform hysterectomy laparoscopically when combined with surgical treatment of endometriosis, unless contraindicated.
  • Mandatory pre-operative discussion points: procedure details, risks/benefits of concurrent oophorectomy, symptom impact, necessity of concurrent lesion excision, recurrence risk, and HRT risks/benefits post-oophorectomy.

8Management of Endometriosis when Fertility is a Priority

• MDTManagement of endometriosis-related subfertility requires multidisciplinary team (MDT) involvement.
  • Must include input from a fertility specialist and access to fertility services.
  • Care may be delivered in secondary gynaecology or tertiary specialist endometriosis services depending on disease severity.
• Do not offer hormonal treatment (alone or in combination with surgery) to patients with endometriosis who are trying to conceive.
  • Rationale: Hormonal suppression does not improve spontaneous pregnancy rates and acts as a contraceptive.
  • Evidence is mixed regarding whether combining hormonal treatments with laparoscopic surgery improves clinical pregnancy or live birth rates compared to surgery alone.
• DefinitionDeep endometriosis is defined as including (but not limited to) endometriosis involving the bowel, bladder, or ureter.

9Staging, Monitoring, and Key Definitions

• Staging vs. Symptoms
  • Offer endometriosis treatment based on the patient's symptoms, preferences, and priorities, rather than the documented stage of endometriosis.
  • The gynaecologist must document a detailed description of the appearance and anatomical site of all endometriosis identified.
• Outpatient Follow-Up Criteria
  • Consider outpatient follow-up (with or without examination and pelvic imaging) for confirmed endometriosis, particularly if the patient chooses non-surgical management, in the presence of:
    • Deep endometriosis involving the bowel, bladder, or ureter.
    • One or more endometriomas larger than 3 cm.
• Non-Pharmacological Management
  • Advise patients that available evidence does not support the use of traditional Chinese medicine, other Chinese herbal medicines, or dietary supplements for treating endometriosis.
• Key Definitions
  • Chronic Pelvic Pain: Pelvic pain lasting for 6 months or longer.
  • Paediatric and Adolescent Gynaecology Service: Hospital-based, multidisciplinary specialist services for girls and young women (usually aged under 18).
  • Ovarian Cystectomy: Surgical excision of an ovarian endometriotic cyst (endometrioma). An endometrioma is defined as a cystic mass arising from ectopic endometrial tissue within the ovary.
  • Managed Clinical Networks: Linked groups of healthcare professionals across primary, secondary, and tertiary care providing a coordinated patient pathway.