Lactulose is a synthetic non-absorbable disaccharide, which is suitable for the treatment of chronic functional constipation by stimulating intestinal peristalsis by allowing more water to enter the intestinal lumen through osmosis, thus keeping the bowels open. Lactulose is not absorbed by the body and is usually metabolized by the intestinal flora, making it a safe and effective constipation treatment. However, the cause of constipation is very complex, and it may be functional or organic constipation. The use of lactulose is only symptomatic treatment, treating the symptoms but not the root cause, and long-term use of lactulose in large doses may cause abdominal pain and diarrhea, and even electrolyte disorders in severe cases. Some patients may also develop dependence, which may aggravate the symptoms of constipation. Therefore, it is still recommended that patients seek medical attention in a timely manner to clarify the specific cause through examination and then carry out cause-specific treatment. In the case of chronic functional constipation, the main thing is to carry out dietary modifications and eat more vegetables and fruits rich in dietary fiber, such as spinach, celery, oranges, bananas, corn and so on. It is important to drink appropriate water to increase stool looseness, maintain good bowel habits, exercise appropriately to promote intestinal peristalsis, relax and avoid excessive stress. Patients can use lactulose as well as prokinetic drugs according to medical advice when they are undergoing medication. In case of organic constipation, such as congenital megacolon, intestinal tumor, etc., surgical treatment may be required.