The causes of children not having stool for 5-6 days include the following: first, children with digestive tract abnormalities, especially in newborn children, if they have not had stool for 5-6 days, they need to rule out any digestive tract abnormalities, such as anal atresia. Secondly, if the child is older than one month, a prolonged absence of stool for 5-6 days is often due to functional constipation. In this case, the child can be treated with probiotics in time, such as the application of small Pepcid and Mamma’s Aid for children to regulate. Finally, children with other diseases, such as congenital megacolon, may not be able to feel the stimulation of the fecal mass effectively due to the absence of nerve cells in the intestine, which may also cause children to have no stool for 5-6 days.