Endometriosis

Endometriosis is a chronic inflammatory condition in which tissue similar to the endometrium (uterine lining) grows outside the uterus — most commonly on the ovaries, fallopian tubes, peritoneum, and rectovaginal septum. These implants respond to hormonal fluctuations, causing inflammation, scar tissue (adhesions), and cyst formation (endometriomas). Endometriosis affects an estimated 10% of reproductive-age women worldwide — approximately 11 million Americans — and is a leading cause of chronic pelvic pain and infertility. The ACOG Practice Bulletin 114 and its updates are the primary clinical guideline. Diagnosis is classically confirmed by laparoscopy with biopsy, though clinical diagnosis is increasingly accepted to reduce diagnostic delay. The condition is often misdiagnosed as functional dysmenorrhea, IBS, or pelvic inflammatory disease.

• Severe menstrual cramps (dysmenorrhea) — often rated 7–10/10 pain, not controlled by OTC medications
• Chronic pelvic pain between periods
• Pain with intercourse (dyspareunia), particularly deep penetration
• Pain with bowel movements or urination, especially during menstruation
• Heavy or irregular menstrual bleeding
• Bloating and gastrointestinal symptoms mimicking IBS
• Fatigue, especially during menstruation
• Difficulty becoming pregnant (infertility)

There is no blood test or imaging study that definitively diagnoses endometriosis — pelvic ultrasound can identify ovarian endometriomas but misses peritoneal implants. MRI performed by a radiologist experienced in endometriosis is more sensitive for deep infiltrating disease. Laparoscopy with direct visualization and biopsy of implants remains the gold standard for diagnosis, but clinical diagnosis (without surgery) is now acceptable per ACOG and ESHRE guidelines when presentation is classic and initiation of empirical treatment is preferred to surgical delay. CA-125 is elevated in some endometriosis patients but is nonspecific and not recommended as a routine diagnostic tool.

Treatment is individualized based on pain severity, desire for fertility preservation, and extent of disease. First-line medical management includes NSAIDs (ibuprofen, naproxen) for pain relief and hormonal suppression: combined oral contraceptive pills (OCPs), progestin-only pills, levonorgestrel IUD (Mirena), or depot medroxyprogesterone acetate (Depo-Provera). GnRH agonists (leuprolide) and antagonists — including elagolix (Orilissa), FDA-approved specifically for endometriosis pain — create a temporary low-estrogen state that reduces implant activity. Laparoscopic excision (removing implants) by an experienced surgeon provides better pain relief than ablation (burning implants) and is preferred. Hysterectomy with bilateral oophorectomy is definitive but eliminates fertility. For infertility associated with endometriosis, reproductive endocrinology referral is important.