1　临床资料患者男,74岁,退休干部。患者于1998年初开始大便后滴鲜红色血,但无大便性状及排便习惯改变。2个月后到当地医院就诊,外科医生行直肠指检而诊断为内痔,经对症处理后便血无改善,并常感肛门下坠感,排便次数每天2～3次,为软便,有排不尽感,并出现头昏,全身乏力等贫血症状 1 Clinical data Patients Male, 74 years old, retired cadres. The patient started dropping fresh red blood after bowel movement in early 1998, but there was no change in stool characteristics and bowel habits. Two months later, I went to a local hospital for treatment. The surgeon performed digital rectal examination and was diagnosed with internal hemorrhoids. After symptomatic treatment, there was no improvement in blood in the stool, and she often felt a sense of falling in the anus. The frequency of defecation was 2 or 3 times per day. It was soft stool and there was no row. Exhausted, and dizziness, generalized fatigue, and other anemic symptoms