Newborns who do not have a bowel movement for 5 days but have foul-smelling farts are generally considered abnormal, and can be seen in functional constipation, congenital megacolon, and other conditions. For newborns, there are individual differences in the pattern of bowel movement, but also with the feeding method and so on, for 5 days without defecation, although there is gas, generally considered abnormal. Normally, formula-fed babies usually have 1~2 bowel movements per day, some of them may have a bowel movement every other day, and the bowel movement is regular and smooth. Breastfed babies may have more frequent bowel movements, about 2~4 times per day, and some of them may have more, but their growth and development are normal, and their weight gain is good. The above phenomenon can be seen in constipation, such as functional constipation, with a significant prolongation of the interval between bowel movements, which can also be accompanied by dry stools and difficulty in defecation. Constipation can also be seen in congenital megacolon disease, which is caused by factors such as absence of ganglion cells in the colon, a history of delayed expulsion of fetal stools, and constipation, with some babies having enemas to pass stools. It is recommended that newborns who have not had a bowel movement for 5 days should seek prompt medical attention and be evaluated by a specialist.