One-month-old babies can take lactulose under the guidance of a doctor, avoiding excessive dosage. Lactulose is a synthetic sugar substance that is not absorbed by the intestinal tract and has the effect of laxative. Lactulose in the intestinal bacteria under the action of the decomposition of low molecular organic acids, can reduce the pH value of the colon and improve osmotic pressure, stimulate intestinal peristalsis and increase the water content of feces, to improve the effect of constipation, lactulose itself is not absorbed by the human body, and part of the fecal matter can be discharged with the body, has a high degree of safety, so one month baby can be applied under the guidance of a doctor. It should be noted that children with autosomal recessive hereditary fructose intolerance should be cautious when taking this product, one month baby taking lactulose can be lukewarm water, to avoid overdose, closely observe the baby with or without abdominal distension, nausea, vomiting, anorexia, diarrhea and other conditions, if necessary, timely pediatrics, to take targeted treatment.