Diarrhea after fever in a one-and-a-half year old baby may be diarrhea disease. Treatment includes dietary adjustments, prevention and correction of dehydration, and rational use of medication. 1. Adjust the diet: diarrhea due to the gastrointestinal tract absorption is reduced, should be emphasized to continue to eat and drink, to meet the physiological needs of the amount. Those with severe vomiting can be temporarily fasted, and resume diet after improvement. 2. Preventing and correcting water and electrolyte disorders: rehydration therapy to prevent shock, potassium supplementation, calcium supplementation therapy. 3. Reasonable use of medication: patients with mucus, pus and blood stools use antibacterial drugs to control infection, such as E. coli infection can be used erythromycin. Intestinal mucosal protective agents can be used to maintain the absorption and secretion of intestinal cells, such as montelukast powder. If your baby has diarrhea after fever, you should go to the hospital in time for treatment under the guidance of your doctor. Normally, good hygiene should be practiced to avoid infection. All the above medications should be used under the guidance of a doctor, avoid self-medication to avoid adverse effects.