To compare the values of a screening methods by OC-Hemodia and chemical fecal occult blood test (COB) for colorectal cancer in elderly people.

• 比较免疫学OC hemodia法抗人血红蛋白单克隆抗体大便潜血试验与化学法大便潜血试验对老年人大肠病变筛选的价值。