Stomach pain and diarrhea are mostly manifestations of acute gastroenteritis, when rehydration and proton pump inhibitors should be given. For patients with mild dehydration, they can be treated by oral rehydration salts; for patients with diarrhea accompanied by obvious vomiting and more obvious dehydration, they can be treated by intravenous fluids. Acid-suppressing drugs are mainly proton pump inhibitors, which can inhibit the secretion of stomach acid and relieve stomach pain, mainly including omeprazole, pantoprazole, rabeprazole, etc. As for diarrhea, there is no need to take anti-diarrheal drugs blindly. After the basic cause is removed, diarrhea can be stopped naturally. If the diarrhea is infectious, antibiotics should be added to fight the infection. For more severe diarrhea, antidiarrheal medications such as montelukast can be applied in small amounts.