Giant rectal intramural hematoma following endoscopic submucosal dissection successfully treated with conservative therapy: A case report

BACKGROUND Endoscopic submucosal dissection (ESD) is a viable therapeutic approach for laterally spreading tumors; however, delayed intramural hematoma remains a rare but serious complication. This report describes a successfully managed case, adding valuable evidence to the existing literature. This study demonstrates that conservative management can be both safe and effective, despite previous reports of fatal outcomes. This experience underscores the importance of early recognition and appropriate management of this complication by endoscopists. CASE SUMMARY A 60-year-old male underwent ESD due to a rectal laterally spreading tumor. The procedure was completed successfully, and the initial postoperative course was uneventful. On postoperative day 4, the patient developed hematochezia accompanied by a drop in hemoglobin level. Emergency colonoscopy revealed a large intramural hematoma at the ESD site. The patient was treated with conservative therapy including bowel rest, bed rest, antibiotics, and hemostatic agents. The following day, the patient developed abdominal distension and constipation, which were managed conservatively. His condition stabilized, and hemoglobin levels remained stable. By postoperative day 15, symptoms had fully resolved. Follow-up colonoscopy showed near-complete hematoma resolution, and the patient was discharged. Six months later, a well-healed ESD scar confirmed a successful long-term outcome. CONCLUSION Delayed intramural hematoma following ESD can be effectively managed with conservative therapy, resulting in complete recovery.