Infants who do not have bowel movements for a few days and fart foul-smelling farts are mostly considered to be caused by constipation. If the infant does not cry or show any other signs of discomfort, there is generally no need to worry too much. The gastrointestinal function of infants is not yet perfect, if the stools are kept in the intestines for too long, it will lead to fermentation, and then farting is smelly. Oral probiotics can be given to the baby to regulate the intestinal flora to promote bowel movement and help defecation. In addition, if the baby is breastfed, the mother should regulate her dietary habits and avoid eating cold, oily and spicy foods to prevent the baby from suffering from constipation and smelly farts. If the child has not passed stool for more than three days, accompanied by irritability and crying, abdominal distension, abdominal pressure and pain, or even stop passing gas, etc., it is necessary to consult a doctor in time to complete the relevant examinations, to clarify the specific causes of the disease and then carry out symptomatic treatment.