After clinical administration of lactulose, a good bowel movement is usually achieved within 6-8 hours, but the specific may vary slightly. Lactulose is a drug commonly used clinically for the treatment of hepatic encephalopathy and functional constipation. It can produce polysaccharide after absorption in the intestine, which has the ability to adjust the pH value of the gastrointestinal tract and make the pH value of the gastrointestinal tract acidic, thus playing a therapeutic role in hepatic encephalopathy. In addition, lactulose can also promote the absorption of intestinal water and increase the water in intestinal stool, thus playing a laxative and laxative effect. Clinically, it is generally recommended to be taken several times, orally 1-3 times daily, with relatively few side effects. The clinical application of lactulose must pay attention to the contraindications and should be applied under the guidance of a doctor. If serious acidosis is caused by various reasons, especially renal failure and other conditions, it is not recommended.