Constipation is a common symptom. Surveys using the Rome III criteria found constipation in at least 10–20% of children in Japan. The children who visit the doctor primarily complaining of constipation may have more than moderate levels of chronic constipation and a gradual decline in rectal sensitivity, which may be unnoticed by them or their families. Since they are suffering from various symptoms, it is better to start medication immediately rather than wasting time with general guidance on lifestyle and diet. It is effective to introduce lifestyle guidance once medication has alleviated symptoms to a certain extent and the patient feels more comfortable. The goal of treatment is to achieve a “nonconstipated state,” defined as having bowel movements at least three times per week that are easy and complete, without a sensation of incomplete evacuation. Fecal impaction. If present, it must be removed. After disimpaction or in cases without impaction, a combination of oral and transrectal treatments is used to maintain a “nonconstipated state.” Sometimes it takes months or years to achieve nonconstipated state without pharmacological treatment. So it is important that every caregivers around the child understand the knowledge of constipation and body. Mild constipation children should be treated by improvement of lifestyle.