The duration of lactulose administration is difficult to define specifically, and the amount, frequency and duration of administration need to be determined according to the patient’s specific situation. Lactulose is mainly used to increase intestinal volume through hypertonicity and stimulate intestinal peristalsis, thus playing the role of promoting bowel movement. In clinical practice, it is mainly used for patients with hepatic encephalopathy and patients with constipation. If patients with hepatic encephalopathy have a controlled diet and can keep their bowel movements open every day, they do not need to apply lactulose for a long time, but only when they have irregular bowel movements. If a patient with hepatic encephalopathy has diabetes mellitus, lactulose should be used with caution and other laxative drugs can be used. In addition, patients with simple constipation should not take lactulose for a long time, but should try to slowly get rid of the dependence on medication by drinking more water, adjusting the diet structure and exercising more.