In 240 patients that obvious foci were not found in rectum, 31 were adenoma.In 31 patients with adenoma, 4 were slight protrude type, 23 were flat type, and 4 were depressed type.

• 在对肉眼未发现明显病变的240例病人中直肠再用0.；5%25美蓝液染色进行观察，发现黏膜改变31例，其中4例为稍隆起型、23例为平坦型、4例为凹陷型。