Four-month-old baby stool yellow with mucus, if the mucus is less, no obvious sour odor, may be a normal situation, do not need to worry too much. If the mucus is more and the sour odor is heavier, it is considered a disease state, which may be improper feeding, acute gastroenteritis, allergic enteritis and other diseases. If the baby’s stool is yellow and has a very small amount of mucus, but no obvious sour odor, it is normal. As the intestine itself can secrete a little mucus, this is a normal physiological phenomenon. However, if there is a lot of mucus in the stool, even like snot, it may be due to improper feeding, acute gastroenteritis, allergic enteritis. It is recommended to seek prompt medical attention and be evaluated and handled by a specialist. Four-month-old babies with yellow mucus in the stool, if the mucus is more visible in a variety of diseases, it is recommended to consult a doctor in a timely manner, improve the relevant examination, to clarify the cause of the disease, and then give targeted treatment or treatment.