大肠恶性肿瘤引起的下消化道大出血少见,其诊断和处理有特殊性。我院1982～1997年共收治大肠恶性肿瘤913例,20例（2.2％）引起大出血。报道如下。l临床资料男14例,女6例。年龄17～81岁,平均46.2岁。所有病例均经手术和病理证实。其中结肠腺癌15例,原发性结肠恶性淋巴瘤2例,大肠 Malignant tumors of the lower intestine caused by massive bleeding of the lower gastrointestinal tract are rare and their diagnosis and management are of special nature. In our hospital from 1982 to 1997, a total of 913 cases of colorectal malignancies were treated, and 20 cases (2.2%) caused major bleeding. The report is as follows. l Clinical data 14 males and 6 females. Age 17 to 81 years old, average 46.2 years old. All cases were confirmed by surgery and pathology. Among them, there were 15 cases of colon adenocarcinoma, 2 cases of primary malignant lymphoma of the colon, and large intestine.