The risk of rotavirus gastroenteritis for infants and children is vomiting and dehydration after diarrhea. Dehydration is not only the loss of water, but also the loss of electrolytes. Rotavirus gastroenteritis is a fierce disease that damages the mucosa of the small intestine very quickly, causing a significant reduction in water absorption by the small intestine mucosa, as well as causing impaired digestion of lactose, increasing intestinal osmotic pressure, causing a large amount of water to enter the intestine, and eventually leading to a large amount of water loss containing electrolytes, causing dehydration. Severe dehydration can cause damage to the brain and other organs, and even endanger life. Parents should give their children a mixture of liquids containing sugar, salt and water such as rice soup and apple juice. By strict standards, “oral rehydration salts” containing electrolytes available at pharmacies are the best choice, as they contain glucose, sodium, potassium and water to prevent and treat mild dehydration. The liquid contains glucose, sodium, potassium and water, and is effective in preventing and treating mild to moderate dehydration. In addition, in home treatment, if the child still does not urinate within 4 hours despite being as hydrated as possible, or even if he or she has fewer tears when crying or a dry mouth, he or she should be seen in the hospital to correct dehydration through intravenous fluids.