The operation process of clean enema includes preoperative indications confirmation and contraindications check, using soap and water or saline enema, and evaluating the effect of enema. 1. Confirmation of indications and contraindications checking (1) Indications: including the treatment of constipation, chronic enteritis, colitis and other diseases, or intestinal cleansing before colonoscopy. (2) Contraindications: including the presence of acute abdominal symptoms, suspicion or presence of gastrointestinal bleeding, pregnancy, congestive heart failure and other conditions, in addition to hepatic encephalopathy prohibited soap enema, sodium retention prohibited saline enema. 2. Enema with soap and water or saline: After helping to set up the position, use the enema device to gradually inject the prepared enema solution such as saline, soap and water, drug solution into the intestinal tract, pay attention to the changes of vital signs during the operation, and stop the operation immediately if there is any serious discomfort or serious fluctuation of blood pressure or heart rate; pay attention to the changes of depth, temperature and position during the process of the enema. 3. Evaluate the effect of enema: after the enema need to assess the enema liquid outflow, abdominal pain, bloating and other abdominal discomfort to improve the situation, rectal mucosal injury and other self-conscious symptoms. Clean enema is an invasive clinical operation, absolutely prohibited without authorization.