肠瘘是指肠与肠、肠与腹腔、肠与皮肤之间的异常通道，肠内容物经此通道进入其他脏器、体腔或至体外。一旦发生肠瘘，患者会出现感染、水电解质紊乱、瘘口周围皮肤糜烂，并发症多，处理难度大，能量消耗大导致营养不良，死亡率高。临床医生常常缺乏对本病的认识，诊断比较困难。本例患者以肛周破溃、皮肤瘘口流脓为主要临床表现就诊。术中探查发现为脓腔位于盆腔骶尾部，包裹膀胱周围，脓腔上方发现一处小肠瘘口，为肠粘连梗阻所致，该病例较为罕见。

An intestinal fistula is an abnormal passage between the intestine and the intestine, the intestine and the abdominal cavity, or the intestine and the skin, through which the intestinal contents enter other organs, the body cavity, or outside the body. Once an enterocutaneous fistula occurs, the patient suffers from infection, water-electrolyte disturbance, skin erosion around the fistula, many complications, difficult management, high energy expenditure leading to malnutrition, and high mortality. Clinicians often lack knowledge of the disease and diagnosis is difficult. In this case, the patient presented with perianal rupture and pus flowing from the cutaneous fistula as the main clinical manifestation. Intraoperative exploration revealed that the pus cavity was located in the sacrococcygeal region of the pelvis and wrapped around the bladder, and a small intestinal fistula was found above the pus cavity as a result of intestinal adhesions and obstruction, which is a rare case.