Because diarrhea removes toxins from the body, the inflammatory response is relieved and the fever improves. If diarrhea is frequent, it is important to rule out the presence of intestinal infections such as bacterial or viral infections. If the diarrhea is severe, it may lead to dehydration and aggravate the fever. It is recommended that the patient should go to the hospital in time when fever and diarrhea occur, and cooperate with the doctor to complete the relevant examinations, such as blood routine, blood biochemistry, C-reactive protein, fecal routine, fecal occult blood test, rotavirus, etc., in order to assist in the understanding of the specific conditions, and cooperate with the doctor to give fluids if necessary. If there is a bacterial infection, antibiotics should be used to control the infection; if there is a viral infection, antiviral treatment is the mainstay, and rehydration and symptomatic supportive therapy should also be given.