Constipation is considered to be a common digestive problem in childhood. It is estimated to affect 5-30% of children, accounting for 3% of visits to primary care and 25% of referrals to pediatric gastroenterologists.1,2 Along with the bowel problems, behavioral issues are found in more than a third of children with constipation.1 Thus, it is responsible for deteriorating the quality of life of children; furthermore, it incurs huge costs to healthcare services as children suffering from constipation are often seen in emergency or admission wards of hospitals.3 Functional constipation is regarded to be the most common type in children accounting for 90-95% cases.1 Although constipation may be characterized by infrequent motions, passage of hard stools and difficulty or pain during defecation, several specific criteria have been proposed by numerous well-known bodies to define this problem in children.1,4 The Northern American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) defines constipation as a delay or difficulty in defecation persisting for two or more weeks.5 The Paris Consensus on Childhood Constipation Terminology (PaCCT) group criteria6 and the Rome IV criteria7 for defining constipation in children are shown in Table 1.