If a three-month-old baby has indigestion and diarrhea: first of all, you can give the baby an abdominal massage to relieve the baby’s intestinal flatulence, promote intestinal peristalsis and the occurrence of intestinal colic, or massage. In addition, you can give your baby oral probiotics to regulate the intestinal bacteria, oral Chinese medicine to strengthen the spleen and stomach. If the stool is very thin, you can take oral montelukast to dry up the stool. If the diarrhea is prolonged, routine stool tests should be performed to rule out bacterial infections, and if there are bacterial infections, oral antibiotics are needed for treatment. If the baby is breastfed, the mother should eat a light diet and avoid foods high in oil and sugar. If the baby is on formula milk and has diarrhea for a long time, she should switch to diarrhea formula, which does not contain lactose and can shorten the duration of diarrhea.