The number of bowel movements in a day of a 4-month-old infant is related to the way he/she is fed. Exclusively breastfed babies have an average of 2-4 bowel movements/day, and some babies have 4-6 bowel movements/day or more; artificially fed babies have dryer and thicker feces, with an average of 1-2 bowel movements/day. Regardless of breastfeeding or formula feeding, it is normal for 4-month-old infants to have 2-3 bowel movements a day without dry stools or difficulty in defecation. It is also normal if they have 1 bowel movement in 3-4 days, but the bowel movement is regular and the nature of the stool is not abnormal. However, if the stools are watery or egg-soup-like, or even mucus or pus-blood stools in severe cases, and the child also has symptoms such as loss of appetite, depression and irritability, it means that diarrhea is abnormal and needs to go to the pediatrician for treatment. If the child suddenly has an increase in the number of bowel movements and a change in the nature of the stools, it is considered diarrhea and should be treated in the pediatrics department of the hospital, and if necessary, a routine stool test should be performed.