Functional constipation (FC), as a prevalent condition in children, is estimated to have a 9.5% prevalence rate worldwide (
1). A clinical-based approach, which is currently based on the pediatric diagnostic Rome IV criteria, is used to diagnose FC in children (
2). The etiology and pathophysiology of constipation in pediatrics is multifactorial, and many factors, including low-socioeconomic status, genetic predisposition, immobility, inadequate fluid, and daily fiber intake, may affect this condition (
3-
5). However, there are still many unknown risk factors. The most common and well-known etiological factor in children is withholding behavior, which usually happens after experiencing the frightening or painful defecation of stools, which may lead to and exacerbated by an anxiety disorder (
1). This behavior is associated with incomplete feces defecation, fecal impaction, dyssynergic evacuation, decreased rectal sensation, and overflow fecal incontinence (
2,
6).
FC puts a heavy burden on children and their parents (
7), and this condition is associated with a decrease in quality of life, decreased academic performance, and psychological disorders including depression, aggression, emotional reactivity, and anxiety (
7,
8). Moreover, FC is more common in children with psychological problems such as autism spectrum disorders (ASDs), attention deficit hyperactivity disorder (ADHD), and different types of anxiety (
2,
9,
10). Another critical disease in such children is less frequent urinary tract dysfunctional disorders such as enuresis, which can simultaneously be observed with FC, thereby arousing further anxiety in children and parents (
11,
12). In these cases, where psychological problem is associated with FC, and there is two-way communication between the two variables, as stress can also affect FC, symptoms may persist by adulthood. Although such cases have received adequate laxative treatment, no improvement in the cases is observed (
13).