Loperamide and Montelukast are both commonly used antidiarrheal drugs in the clinic, and their effects vary from person to person, there is no such thing as who is effective, and it is best to standardize the use of medication under the guidance of a doctor. 1. Loperamide is an antidiarrheal drug that can inhibit the contraction of intestinal smooth muscle, reduce intestinal peristalsis and increase intestinal transit time. It can also enhance the tension of the anal sphincter, thus reducing fecal incontinence. Clinically, it is mainly used to control the symptoms of acute and chronic diarrhea, and can also be used for patients after ileostomy, which can increase the stool consistency and hardness, and reduce the number of bowel movements and the amount of bowel movements. Adverse effects of loperamide include constipation, intestinal flatulence, nausea, headache, dizziness, dry mouth, and abdominal pain. It is contraindicated in those who are allergic to the product; children under 2 years of age are contraindicated; pregnant women should use it with caution, and lactating women should not use it. 2. Montelukast is an antidiarrheal drug, which has a fixing and inhibiting effect on bacteria, viruses and the toxins they produce in the digestive tract, thus making them lose their pathogenic effects. It also has a protective effect on the mucous membrane of the digestive tract, can balance the normal flora and local pain relief. Clinically, it is mainly used for acute and chronic diarrhea in adults and children. Adverse reactions of Montelukast include mild constipation. Its contraindications are not clear. If you need to use the drug, it should be used under the guidance of a doctor, do not use it on your own to avoid adverse effects.