结肠、直肠癌在美国常见的癌症中排第 3位 ,居死亡原因的第 2位 [1 ] 。我国结肠、直肠癌的发病率虽低于美国 ,但近年也呈逐年增加趋势。对结肠、直肠癌进行筛检的目的是查出那些虽无症状和体征 ,但很有可能是潜在疾病者。大量研究结果显示 ,筛检可以明显降低结肠、直肠癌的发? Colon and rectal cancer ranked the third most common cancer in the United States, ranking second in death causes [1]. Although the incidence of colon and rectal cancer is lower in the United States than in the United States, it has also been increasing year by year. The purpose of screening for colon and rectal cancer is to find those who are asymptomatic and physical signs, but are likely to be potential diseases. A large number of studies have shown that screening can significantly reduce the incidence of colon and rectal cancer.