Endometriosis

Endometrial-like tissue outside the uterus, causing a chronic inflammatory, oestrogen-dependent, often progressive condition. For the broader period-pain work-up see Dysmenorrhoea (primary & secondary); for the closely related myometrial condition see Adenomyosis.

Prompt diagnosis matters. RANZCOG and NICE both stress that diagnostic delay (still averaging years) worsens quality of life and may allow disease progression — treat on a clinical diagnosis, don’t wait for laparoscopy.

Presentation

Consider endometriosis in any reproductive-age patient with: chronic pelvic pain (≥6 months), dysmenorrhoea, dyspareunia, dyschezia, dysuria, cyclical haematuria, premenstrual spotting, heavy menstrual bleeding, catamenial GI symptoms, or infertility (diagnosis is only made during infertility work-up in ~30% of cases). Acyclical pelvic pain — constant or intermittent, exacerbated by activity — is common, especially in adolescents, and should not be dismissed as “not typical” endometriosis.

Risk: first-degree relative affected (3–10× risk), early menarche, shorter cycle length, greater height.

Diagnosis

• History (duration/severity, family history, reproductive goals — guides treatment), symptom diary, abdominal + pelvic exam (adnexal/uterine/posterior-fornix tenderness, masses, nodules, fixed pelvic organs).
• Ultrasound (transvaginal preferred) can support diagnosis but a normal scan does not exclude endometriosis — deep infiltrating disease is particularly hard to detect and needs specific sonographer expertise.
• Laparoscopy with histopathology is the gold standard but is not required in everyone. Start treatment on a presumed clinical diagnosis (history + exam ± supportive ultrasound) — don’t wait for surgical confirmation before treating pain.

Referral

Refer to a gynaecologist / specialist endometriosis service if (RANZCOG triggers):

• Imaging suggests higher-stage or deeply infiltrating disease — endometrioma, adenomyosis, or disease invading other organs
• Severe, persistent or recurrent symptoms
• Signs of endometriosis on examination
• Initial management is ineffective, not tolerated, or contraindicated (≈ no response to first-line treatment after 3 months)
• Suspected bladder/bowel involvement (deep endometriosis)
• Trying to conceive: refer for fertility treatment if no conception after 6 months of trying, or if age >35

Refer under-17s to a paediatric/adolescent gynaecologist (or a gynaecologist comfortable managing adolescents) — endometriosis is frequently missed in this group because acyclical or atypical pain is dismissed as “normal” period pain.

Multidisciplinary input (endocrinologist, psychologist, pelvic floor physiotherapist, pain specialist) is often needed given the physical and mental-health burden of the condition.

Management

Analgesia (first-line, alone or with hormonal treatment): 3-month trial of NSAID and/or paracetamol. Endometriotic deposits are innervated and pain can have a neuropathic component — consider this if response is poor.

Hormonal treatment — no option is proven more effective than another; choice is guided by adverse effects, patient preference, and fertility plans. Avoid hormonal treatment while actively trying to conceive (it impairs conception short-term, though not long-term fertility).

Option	Notes
Combined hormonal contraception (COC or vaginal ring)	Cyclical or extended/continuous — continuous is preferred to eliminate menstruation and better control dysmenorrhoea
Long-acting progestogens (52mg LNG-IUD, etonogestrel implant, DMPA)	First-line, not just short-term — an alternative to CHC, particularly if oestrogen is contraindicated; effective symptom control + contraception with low user burden
Oral progestogens (norethisterone, dienogest 2mg/day, medroxyprogesterone)	Reserved for when oestrogen and long-acting progestogens are unsuitable — poorly tolerated (breast tenderness, irregular bleeding, headache), 3–6 month courses, doesn’t reliably contracept (use a non-hormonal method if contraception is wanted)
Danazol	Specialist-only, significant adverse effects (hirsutism, acne, voice change, hepatotoxicity, dyslipidaemia, small ↑ ovarian cancer risk), 6–9 month max
GnRH agonists (goserelin, nafarelin)	Specialist-initiated; hypo-oestrogenic effects limit use to 6 months unless “add-back” oestrogen+progestogen (MHT-equivalent doses) is co-prescribed, extending use to up to 2 years; caution in adolescents (may limit peak bone mass)
Aromatase inhibitors + ovulation suppression	Specialist-only second-line option

Surgery: laparoscopic excision/ablation for severe pain or infertility; further surgery favoured over repeat procedures only for infertility, recurrence despite medical treatment, complications (e.g. bowel adhesions), or deep disease involving bowel/ bladder/ureter (repeated surgery risks scarring, especially relevant if fertility is wanted). Hysterectomy considered if adenomyosis is seen on ultrasound or HMB doesn’t respond to therapy; if bilateral salpingo-oophorectomy is done premenopausally, MHT is required afterwards to protect bone/cardiovascular health.

Ongoing care: a written management plan, pelvic floor physiotherapy for pelvic floor dysfunction/dyspareunia, and psychology input are appropriate parts of long-term care — this is a chronic condition, not something “fixed” by a single treatment. No complementary therapy has established benefit for endometriosis-related pain.