Pelvic Sepsis Secondary to Necrotic Coloanal Anastomosis After Perineal Proctosigmoidectomy Leading to Emergent Abdominoperineal Resection: A Rare Case and Complication

会阴直肠乙状结肠切除术后坏死性结肠肛门吻合口继发盆腔脓毒症，最终行急诊腹会阴联合切除术：一例罕见病例及并发症