Endometriosis

By RRM Academy Reviewed by Dr. Naomi Whittaker, MD, Board-Certified OBGYN, MIGS, NFPMC, FCI Updated June 2, 2026

Endometriosis is a chronic inflammatory condition in which tissue similar to the endometrium grows outside the uterine cavity, most commonly on the ovaries, fallopian tubes, pelvic peritoneum, and uterosacral ligaments. It is common among women of reproductive age and is a significant driver of both pelvic pain and infertility in couples seeking care. Despite its prevalence, the median time from symptom onset to diagnosis is 9 years,¹ a delay driven by normalized dismissal of pelvic pain and dysmenorrhea as routine. Endometriosis causes inflammation, adhesion formation, distorted pelvic anatomy, and impaired tubal and implantation function, all of which affect both the woman's health and a couple's fertility. The standard surgical treatment is laparoscopic excision surgery, which demonstrates significantly greater improvement across symptom domains compared to ablation.² Hormonal suppression after surgery masks disease activity without treating the underlying condition: it does not stop disease progression. For complex pelvic disease, clinicians may employ PEARS, NARPS, or S-MAP techniques alongside adhesion prevention.

Where endometriosis comes from remains an open question. The dominant theory, proposed by Sampson in 1927, holds that menstrual tissue flows backward through the fallopian tubes and implants in the pelvis. This theory has shaped clinical thinking for nearly a century, but it cannot fully explain the disease. Endometriosis occurs at sites menstrual reflux cannot reach: extrapelvic locations, rare documented cases in male patients, and ectopic endometrial tissue identified in human female fetuses at autopsy.³ The research literature describes several competing or complementary theories, including coelomic metaplasia, embryonic-rest and Mullerianosis theories, stem-cell seeding, and lymphovascular spread.⁴ The retrograde-menstruation theory is best understood as insufficient as a sole explanation, not as a settled account of the disease's origin. This matters clinically: if endometriosis is not simply refluxed menstrual tissue, suppressing menstruation does not treat it. The disease requires surgical removal.

Endometriosis is reliably diagnosed only by direct surgical visualization. Ultrasound and MRI frequently miss the disease, particularly small and superficial implants, and tend to detect only larger lesions such as endometriomas. By the time imaging picks up disease, many women are already at an advanced stage. The only definitive diagnostic tool is laparoscopy. Critically, the severity of symptoms does not correlate with disease stage. Severe, debilitating pain can occur with stage I disease. Conversely, some women with stage IV disease have no pain at all and present only with infertility. Stage number alone tells a clinician very little about a patient's symptom burden or fertility risk.

There is no medical therapy that regresses or cures endometriosis. Hormones manage pain, but they do not halt or reverse disease progression. There is no known treatment that acts on established lesions the way a chemotherapeutic agent would. Surgery remains the only means of removing disease. Excision produces significantly greater improvement in pain symptoms, including dysmenorrhea, dyschezia, and chronic pelvic pain, compared to ablation.²⁵ Excision by an experienced surgeon is associated with substantially lower recurrence than ablation or surgery by non-specialists. Recurrence risk varies considerably by disease severity and lesion type; the data is inconsistent across the literature, and each case must be evaluated individually. Surgery is the best diagnostic and treatment tool available. It is not, however, considered a cure.

Endometriosis affects the nervous system, not just the pelvis. The disease can durably remodel sensory nerve pathways, producing peripheral and central sensitization that drives chronic pain.⁶ Because of this neural remodeling, pain may persist in some patients even after lesions are surgically removed. Persistent pain after excision does not always indicate residual disease. It can reflect the lasting impact endometriosis has already had on the nervous system. Effective pain management often requires addressing multiple contributors alongside surgery, including pelvic floor physical therapy and lifestyle factors. The disease is not purely a pelvic structural problem; it is a whole-body inflammatory condition associated with immune dysregulation⁷ and with conditions including irritable bowel syndrome, fibromyalgia, and migraines. Endometriosis also impairs ovarian reserve and oocyte quality over time,⁸ which is one reason early evaluation and treatment matters for couples trying to conceive. The luteal phase can be compromised as well, adding another layer of reproductive dysfunction beyond the structural distortion of the pelvis. Women with endometriosis labeled "unexplained infertility" are frequently undiagnosed: systematic laparoscopic evaluation often reveals disease that prior imaging missed.⁹

This content is for educational purposes only and does not constitute medical advice. Consult an RRM clinician or healthcare provider for guidance specific to your situation.