Adults: constipation: starting dose 15-30 ml daily, preferably once at breakfast, maintenance dose 7.5-15 ml daily, once at breakfast; hepatic coma. and coma. Prophylaxis: starting 30~50 ml 3 times daily, then the dose can be adjusted until 2~3 soft stools are expelled daily is appropriate. Lactulose is available in a variety of preparations and sizes. (Lactulose oral solution, Lactulose powder, Lactulose granules and syrup, etc.) They have different methods of administration, routes and speed of absorption and stability. Preparations from different manufacturers may have different effects and adverse reactions due to different manufacturing processes, and it is recommended that the medication be used appropriately under the guidance of a physician. Adverse reactions include mild abdominal pain and burning sensation, and large doses of the drug may cause abdominal discomfort, flatulence, anorexia, nausea and vomiting. Hypernatremia has been reported in rare cases when treating hepatic encephalopathy. It is contraindicated in those who are allergic to the product and the ingredients contained therein, appendicitis, intestinal obstruction, unexplained abdominal pain, acute abdominal pain and concomitant use of other laxatives, diabetic patients, patients with galactosemia, intolerance to lactose and fructose, galactose, and patients with uremia. Use with caution in children, pregnant and lactating women. If you need to take lactulose for the corresponding symptoms, you should follow the instructions of a professional physician, its usage, dosage, duration of use and so on. Do not self-medicate at home without authorization in accordance with the instructions of the drug.