Anal examination, which is rectal palpation. The correct examination positions are left lateral recumbent position, knee-chest position, truncated position and squatting position. 1. Left lateral recumbent position: a commonly used position for rectal examination, lying down on the left side of the body, the right leg to the chest flexion, full exposure of the anus. It is suitable for most people to check. 2. Knee-chest position: It is a common position for checking the rectum and anal canal. The patient lies on the examination bed, and the knees are bent and folded in front of the chest. As this position requires high degree of cooperation from the patient, it should be used with discretion for the elderly, the weak and the seriously ill. 3. Stone position: the patient lies on the examination bed, the popliteal fossa is placed on the support frame on both sides of the bed, exposing the anus. The position is often chosen for double diagnostic examination. 4. Squatting position: suitable for the examination of rectal prolapse, three stages of internal hemorrhoids and lower polyps. Rectal canal due to the maximum pressure in this position, can drop 1 ~ 2cm, so you can see the internal hemorrhoids or prolapse of the most serious situation. Rectal diagnosis is a simple but important clinical examination method, which is of great significance for the early detection of anal canal and rectal cancer. Position is very important in rectal diagnosis, improper position may cause pain or even leakage of diagnosis, and suitable position should be selected under the guidance of physicians according to the purpose of examination and the physical condition of patients.