Can endometriosis cause pain during defecation?

Endometriosis Can Cause Pain During Defecation

Yes, endometriosis commonly causes pain with defecation, particularly when it involves the bowel wall or rectosigmoid area. 1 This symptom is a direct result of deep infiltrating endometriosis affecting the intestinal tract, with the anterior wall of the rectosigmoid colon being the most common location for bowel endometriosis.

Anatomical Basis for Defecation Pain in Endometriosis

• Bowel Involvement: The intestinal tract is the most common site of non-gynecologic endometriosis 2

• Distribution of Lesions: Endometriotic lesions in the bowel follow this pattern of frequency:

  • Anterior wall of rectosigmoid colon (most common)
  • Sigmoid colon
  • Cecum and ileocecal valve
  • Appendix
  • Small bowel 2

• Depth of Invasion: Pain severity correlates with depth of lesions rather than extent of visible lesions 1

  • Endometriosis can infiltrate the muscular bowel wall, leading to gastrointestinal symptoms 2
  • Lesions involving the muscular layer may require more extensive surgical intervention (discoid or segmental resection) 2

Clinical Presentation of Bowel Endometriosis

Patients with bowel endometriosis typically present with:

• Pain during defecation (dyschezia)
• Alterations in bowel habits:
  • Constipation
  • Diarrhea
  • Tenesmus (feeling of incomplete evacuation)
• Rarely, rectal bleeding 3
• Pain that may be cyclic (worsening during menstruation) 4
• Unusual presentations may include epigastric pain that occurs only during menstruation 4

In severe cases, bowel endometriosis can lead to acute mechanical intestinal obstruction, though this is rare, occurring in 7-23% of gastrointestinal endometriosis cases 5.

Diagnostic Approach

For patients presenting with pain during defecation who are suspected of having endometriosis:

1. Imaging Studies:

   • Transvaginal Ultrasound (TVUS): First-line imaging modality

     • Expanded TVUS protocols with additional scanning maneuvers have excellent performance for detection of deep endometriosis 2
     • The uterine sliding sign has good diagnostic performance for detection of endometriosis involving the bowel and pouch of Douglas 2

   • Combined Transabdominal and Transvaginal Ultrasound:

     • Excellent sensitivity and specificity for rectosigmoid lesions
     • Slightly decreased sensitivity for sigmoid lesions 2
     • Transabdominal component helps identify sites of bowel involvement beyond the pelvis 2

   • MRI Pelvis:

     • Helpful for diagnosis of deep endometriosis and treatment planning 2
     • 92.4% sensitive and 94.6% specific in detecting intestinal endometriosis 2
     • Can predict surgical approach based on morphologic characteristics of lesions 2

   • Transrectal Ultrasound:

     • Allows evaluation of bowel wall layers involved by endometriotic lesions 2
     • 97% sensitive and 96% specific for detection of rectovaginal endometriosis 2

2. Definitive Diagnosis:

   • Gold standard is laparoscopy with histologic confirmation 1

Management Considerations

For patients with confirmed bowel endometriosis causing pain with defecation:

1. Medical Management:

   • First-line: Hormonal treatments
     • Combined oral contraceptives
     • Progestin-only options
     • GnRH agonists/antagonists 1

2. Surgical Management:

   • Consider when medical therapy is ineffective or contraindicated
   • Surgical options depend on lesion depth and extent:
     • Superficial lesions: Rectal shaving
     • Deeper lesions involving muscular layer: Discoid or segmental resection 2
   • Laparoscopic approach is standard of care 3
   • Long-term outcomes after bowel resection for severe endometriosis are generally good 3

Important Clinical Considerations

• Pain with defecation may be the primary presenting symptom even when other classic endometriosis symptoms are absent
• Symptoms may be cyclic, worsening during menstruation 6
• Recurrence rates can be high (25-44% within 12 months of discontinuing hormonal treatment) 1
• Anastomotic complications occur in approximately 1% of surgical cases 3

Bowel endometriosis should be considered in the differential diagnosis for any woman of reproductive age presenting with pain during defecation, especially if symptoms worsen during menstruation or if there is a known history of endometriosis.