A 5-year-old baby who has diarrhea should drink more water. If oral rehydration salts are available, you can take oral rehydration salts. Oral rehydration salt has a certain ratio of water and electrolyte content, which can effectively prevent the occurrence of dehydration and electrolyte disorders. The diet should be light and easy to digest, you can eat easy to digest green vegetable porridge or millet porridge, are good choices. In addition, you can give your baby probiotics to regulate intestinal flora. If the stool is very thin, you can take oral montmorillonite before meals. Montmorillonite can cover the surface of the intestine and form a protective film, thus making the stool dry. If the stool turns dry, stop montelukast in time. If the diarrhea is prolonged and the stool contains mucus or blood, a routine stool test should be performed. If it is bacterial enteritis, anti anti-infective treatment should be administered.