The main cause of this condition is in the texture and quantity of the complementary food. If the added complementary foods are not easily digestible, such as not cooked badly enough, or added in large amounts or varieties at a time, or if the complementary foods are not hygienic, they may lead to diarrhea. Babies can add complementary foods from the age of 4 to 6 months. The principles of adding complementary foods: 1. From thin to thick: Generally, you should add liquid foods such as rice soup first, and then add semi-liquid foods such as porridge, and gradually add solid foods such as cookies and baked bread pieces. 2, from less to more: add food can be less at first, and then gradually increase the amount of food, can not be too hasty. 3, from one to many: add food, each time only add one, after 4-5 days, if the baby does not have indigestion or allergic reactions, mental appetite are normal, then add a second, step by step, so as not to cause indigestion. 4. It is best to add complementary foods regularly and quantitatively, the food should be fresh and pay attention to food hygiene. In this baby’s case, you can suspend the addition of complementary foods or reduce the amount of complementary foods, and then continue to add complementary foods after the stool turns better.