A rare case of life-threatening haematochezia in pregnancy associated with decidualized rectal mucosal endometriosis

STUDY OBJECTIVE: To report and emphasize the difficulty in diagnosis and management of acute gastrointestinal bleeding due to recurrent endometriosis in pregnancy. DESIGN: Image article. SETTING: 35 years old, primigravida who is a known case of recurrent endometriosis. She was first diagnosed with ovarian endometriosis and underwent open right endometriotic cystectomy (2017). She had rectovaginal, bilateral ovarian endometriosis associated subfertility and severe pain for which laparoscopic clearance was done (2022). She was symptom free for 3 years. She conceived via in vitro fertilization (2025). She presented to emergency in shock at 12 weeks of gestation due to hematochezia. Despite medical management, there were continued episodes of hematochezia. Ultrasound, MRI, upper gastrointestinal endoscopy and sigmoidoscopy were inconclusive. A suspected vascular bleed at rectosigmoid junction was found during MR angiography. Her worsening state warranted active intervention. INTERVENTION: Angiographic coil embolization. MAIN RESULTS: After embolization the intensity of hematochezia reduced and stopped over the next few days. At follow up after 15 days, colonoscopy revealed a circumferential ulcerated lesion at rectosigmoid junction where a biopsy was taken. Histopathology and immunohistochemistry were consistent with decidualized rectal mucosal endometriosis. CONCLUSION: Extragenital endometriosis of the gastrointestinal tract accounts to 5.4% of endometriosis patients [1]. However, endometriosis is a very rare cause of lower gastrointestinal bleeding [1]. The gold standard for diagnosis remains to be histopathology [2]. Intestinal mucosal endometriosis poses diagnostic hurdles in terms of lack of clear colonoscopy results, particularly biopsy [1,2]. Decidualisation of ectopic endometrial tissue causes reduction in lesion size, necrosis related weakening of wall and unexpected haemorrhage or even bowel perforation [see TABLE 1]. The tall tale of how pregnancy can quiescent endometriosis can lead to serious complications [7]. So far, few such cases have been reported [see TABLE 2]. Therefore, physicians should consider such acute life-threatening complications in pregnant women with known endometriosis [7].