In general, montelukast can be used to stop diarrhea after 2-3 hours of administration. The specific onset of action time is related to the severity of the disease, physical condition and other conditions. In clinical practice, montelukast is mainly used for the treatment of diarrhea caused by various diseases, and can provide some relief for painful symptoms in the esophagus, stomach, intestines and other local tissues caused by digestive tract diseases. In general, most patients can achieve diarrhea relief within 2-3 hours after the administration of the drug. However, it should be noted that due to the strong antidiarrheal effect of montelukast, improper use may lead to adverse reactions such as dry stools and irregular bowel movements. If overdosed for a long time, it may also affect the absorption of trace elements such as potassium, iron and magnesium into the intestinal tissues, thus causing muscle tissue weakness, intestinal dysfunction, malnutrition and other problems. It should also be noted that when montelukast is co-administered with other types of drugs, it should be taken after a half-hour interval to avoid affecting the absorption and utilization of other drugs by the gastrointestinal tissues.