Lactulose oral (soluble) solution does not usually lead to gain weight after drinking, the specific use of medication as prescribed by the doctor. Lactulose oral solution can stimulate colonic peristalsis, keep the bowel movement, can also stimulate the bacteria to use ammonia for protein synthesis, improve ammonia metabolism, suitable for the treatment of chronic constipation, prevention and treatment of hepatic encephalopathy. Adverse reactions of mild abdominal pain and burning sensation may occur after administration, while abdominal discomfort, gastrointestinal flatulence, anorexia, nausea, vomiting and abdominal pain, diarrhea, electrolyte disorders and other adverse reactions may occur with high doses of the drug. The drug does not generally cause adverse reactions of weight gain. The drug should be contraindicated in people who are allergic to lactulose and its components, diabetics, patients with galactosemia, people suffering from uremia, perforation of the digestive tract, appendicitis, acute inflammatory bowel disease, intestinal obstruction, unexplained abdominal pain, as well as those who concomitantly use other laxatives. Specific medication should be used under the guidance of a specialist, and should not be used without authorization.