Under normal circumstances, the number of times a four-month-old baby is defecated in a day is related to feeding methods and individual differences, and needs to be analyzed on a case-by-case basis. The number of bowel movements per day can reflect the physiological and pathological state of the baby’s gastrointestinal tract, and therefore fecal examination is an important part of pediatrics. Regarding the normal number of bowel movements per day, there are individual differences, and it is also related to the baby’s feeding style and weight gain. Four-month-old babies usually do not add complementary foods, such as breastfeeding, in general, the number of bowel movements per day is 2~4 times, or some babies often have 4~5 or even 5~7 times of bowel movements per day, but the nature of the stool is not dilute, the baby’s general condition is good, and the weight gain is good, then it can not be regarded as a pathological state, and the number of times usually decreases gradually after the addition of complementary foods. For cows’ and goats’ milk-fed babies of this age group, the normal number of stools is usually 1~2 times a day. When there is a sudden increase or significant decrease in the number of stools, accompanied by crying and discomfort or growth and developmental abnormalities, it is recommended that the baby be seen by a specialist for a comprehensive assessment and judgment.