Rectal diagnosis cytology detection technology sampling and characteristics: routine rectal diagnosis, the examination of the finger sleeve with the secretion immediately coated in 2-3 slides, with 95% alcohol fixation, staining, smear should be rubbed over, so that the glass slide covered with clouds can be, do not apply the overly thick or repeated smear, so as not to affect the field of view and lead to cell destruction; sampling is not ideal, you can be the finger sleeve wrapped in gauze, in the lesion or the squamous junction mucosa repeatedly rubbed to obtain more effective results. When it is unsatisfactory to take the material, the finger sleeve can be wrapped in gauze and rubbed repeatedly on the mucous membrane of the lesion or squamous-column junction to obtain more secretion, which is more effective. Clinical significance: (1) Non-invasive examination, little pain, low cost, and the diagnostic compliance rate of rectal cancer reaches 90%. (2) It has high screening and reference value for early detection of rectal lesions and cancer. (3)It has good diagnostic value for tumor, microorganism (such as fungus, etc.) and inflammatory lesions of rectum. (4) The anal diagnosis with pathological cytology examination can make the disease diagnosis more comprehensive and more specific; at present, all the major hospitals in the country have made it as the routine examination and compulsory physical examination program. (5) In view of the simplicity, rapidity and economy of this technique, the examined person does not feel pain or has less pain, it is suitable for the tumor census of the population and can diagnose the early or hidden malignant tumors, which plays an important significance for the early detection, diagnosis and treatment of tumors.