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Concept created 2026-08-25 · updated 2026-08-25
colorectalendometriosisgynecologydeep-infiltrating-endometriosisbowel-resection

Colorectal Endometriosis

Filed as a concept page rather than a condition page: endometriosis is fundamentally a gynecologic disease (see ASCRS Ch41 - Endometriosis for the full gynecologic epidemiology, etiology, staging, and medical-management picture), and this page deliberately covers only the subset relevant to a colorectal surgeon — recognizing bowel-involving disease, and the surgical technique/outcomes of resecting it. Colorectal surgeons become involved when deep infiltrating endometriosis (DIE) infiltrates the rectosigmoid, typically via combined procedures with gynecology.

Presentation and diagnosis (colorectal-relevant)

Bowel-involving DIE presents with cyclical (menstruation-associated) rectal bleeding, dyschezia, constipation, tenesmus, or — in advanced disease — bowel obstruction from luminal stenosis (see Large Bowel Obstruction, where endometriosis is noted as a rare cause, <1% of LBO). Colonoscopy has a limited diagnostic role: DIE lesions are typically extrinsic/submucosal, so the mucosa is often spared even with transmural bowel-wall infiltration, and biopsy can be falsely reassuring. Rectal endoscopic ultrasound can assess bowel-wall-layer involvement depth. Pelvic MRI and transvaginal ultrasound (TVUS) are the primary staging/planning modalities; a "negative sliding sign" on TVUS (loss of normal rectum-on-posterior-vagina/cervix mobility) suggests pouch-of-Douglas obliteration and rectal adhesion, useful preoperative planning information for a combined gynecology-colorectal case.

Surgical management of bowel-involving disease

Laparoscopic approach is standard. Technique is selected by lesion size, depth, and location:

  • Shaving — excising superficial disease off the serosal/muscularis surface without entering the bowel lumen; lowest complication rate of the three techniques; appropriate for superficial implants.
  • Disc excision — full-thickness excision of a focal lesion (typically <3cm) with primary transverse closure or a circular stapler, avoiding a segmental resection and its anastomosis.
  • Segmental resection — for larger, circumferential, or multifocal disease, or for stenotic lesions causing luminal narrowing; involves a formal bowel resection and anastomosis, following the same anastomotic-construction principles as any colorectal resection (see Anastomotic Construction).

Complication rates range 2.9–25% depending on the extent of DIE and whether bowel resection was performed, including anastomotic leak, anastomotic stricture, fistula, and voiding dysfunction (from pelvic autonomic nerve injury during deep dissection — shared risk territory with rectal cancer TME surgery). Sexual-function outcomes (via KFSP-type instruments) have been compared across the three techniques in the source chapter's cited literature, without a clearly superior approach identified. Anastomotic stenosis after segmental resection is managed with endoscopic dilation first-line, reserving redo surgery for refractory cases.

Recurrence

Reported recurrence after surgery ranges widely (6–67%), depending on definition used, follow-up duration, and technique; risk factors include younger age at surgery, incomplete excision, and higher r-ASRM stage at diagnosis (gynecologic staging system — see ASCRS Ch41 - Endometriosis for detail).

  • ASCRS Ch41 - Endometriosis — source chapter (full gynecologic detail: etiology theories, r-ASRM/ENZIAN/EFI staging, medical management, ovarian cancer association).
  • Large Bowel Obstruction — endometriosis as a rare (<1%) cause of LBO via rectosigmoid luminal stenosis.
  • Anastomotic Construction — general anastomotic technique/complication principles applicable to segmental resection for DIE.

Open items / gaps

  • The complication-rate (2.9–25%) and recurrence-rate (6–67%) ranges are wide, textbook-level syntheses without primary-study breakdown by technique or DIE extent — a systematic review or meta-analysis directly comparing shaving/disc excision/segmental resection outcomes would be the highest-value next ingestion for this page.
  • Gynecologic staging systems (r-ASRM, ENZIAN, Endometriosis Fertility Index) are named but not detailed here — see the source chapter if that level of detail becomes relevant to a future combined-procedure page.