Rare submucosal abscess following endoscopic mucosal resection for rectal polyps: a case report and literature review.

Colonoscopy combined with polypectomy is a well-established strategy for the prevention of colorectal cancer, and endoscopic mucosal resection (EMR) serves as one of the primary therapeutic modalities for colorectal neoplastic lesions. While EMR is generally safe, severe complications may occasionally occur. Herein, we report a rare case of rectal submucosal abscess in a 74-year-old female patient who underwent EMR for rectal polyps. Initial endoscopic fenestration and drainage of the abscess failed to achieve a satisfactory therapeutic effect, and the patient ultimately underwent sigmoidostomy for further management. This case highlights the necessity of considering phlegmon or abscess formation in the differential diagnosis of patients presenting with unexplained acute abdomen after EMR for rectal lesions, especially in those with compromised immunity. Timely identification and intervention are crucial to avoid adverse clinical outcomes.