Continuous Amenorrhea May Be Insufficient to Stop the Progression of Colorectal Endometriosis

We present the case of a patient in whom consecutive imaging assessment and surgery demonstrated the obvious progression of colorectal endometriosis under continuous medical therapy. A 26-year-old nullipara presented with secondary dysmenorrhea, deep dyspareunia, diarrhea, and constipation during menstruation. Magnetic resonance imaging (MRI) assessment revealed 2 right ovarian endometriomas, but no deep endometriosis lesion. Intraoperatively, we found a 2-cm length of thickened and congestive area of sigmoid colon, along with small superficial lesions arising in the small bowel and appendix. We performed ablation of ovarian endometriomas and appendectomy, and decided to not resect the bowel. Postoperative computed tomography-based virtual colonoscopy (CTC) revealed a slight abnormality of the sigmoid colon. Endorectal ultrasound identified a normal rectum and sigmoid colon. Despite long-term continuous medical treatment, the patient presented 4 years later with impaired digestion consisting in constipation alternating with diarrhea, bloating, dyschesia, and pelvic pain. MRI and CTC revealed an abnormal sigmoid colon from 42 to 50 cm above the anus, with digestive tract diameter reduced from 10 mm down to the virtual lumen, along with an overall rigid appearance. Laparoscopy revealed the extent of endometriosis lesions in the sigmoid colon and multiple implantations in the small bowel. We performed sigmoid and small bowel resection. This case demonstrates the obvious progression of deep rectal endometriosis despite 4 years of continuous hormonal therapy.