Because saline enema is a more specialized operation, it needs to be carried out under the guidance of a professional doctor, and it is not recommended to carry out saline enema at home by yourself. Saline purging is the more commonly used enema method in the clinic, and its preparation tools mainly include saline, enema and anal tube. The procedure is to add 800~1000 ml of saline into the enema, connect the anal tube with the head of the syringe, and control the temperature of the saline at about 40℃. The patient should take the left lateral position, the anal tube is slowly inserted into the anus about 10 cm, slowly injecting the saline water, retaining about 10 minutes to soften the feces, and play the role of purging. It is worth noting that saline bowel cleansing is a more professional operation, it is recommended to go to a regular hospital under the guidance of a professional doctor, do not operate on your own.