Abstract
Delayed anastomotic submucosal abscess is a rare complication of rectal tumor resection. A submucosal tumor-like lesion near the anastomotic site was detected in a 57-year-old woman, and pus and sutures were found through spontaneously formed fistulas. Endoscopic ultrasound confirmed the presence of hyperechoic pus flowing out from the fistulas on compression of the lesion. The patient recovered well without surgery. This case indicates that submucosal abscess should be taken into consideration if suspected submucosal tumor-like lesions are detected after rectal surgery. Endoscopic drainage combined with antibiotic treatment may be an effective strategy for limited postoperative anastomotic abscess.