This study aimed to evaluate the effectiveness, safety, and document the reported adverse effect of a herbal-based laxative (Goleghand^®) for the maintenance treatment of functional constipation in young children. Methods: We conducted a randomized clinical trial from April 2019 to September 2020. Children aged 2–15 years with functional constipation defined according to the Rome IV criteria were eligible for study inclusion. Eligible children were randomly allocated to receive polyethylene glycol (PEG) or Goleghand^®. The number and consistency of stools per day, painful defecation, abdominal pain, and fecal incontinence were reported weekly by parents. The statistical analyses were performed by determining means and standard deviations, t-test, Chi-square test, ANOVA repeated measures, and Fisher's exact test, with significance, accepted at the 5% level. Findings: Sixty patients have been enrolled in the study. Parental satisfaction scores did not change significantly in either group or over the follow-up period. Our results showed that the effect of time (P < 0.001) and also the effect of group type (P = 0.01) on the number of fecal defecations was significant. The mean number of defecations increased first and then decreased significantly over time, but this decrease was more significant in the PEG group than in the Goleghand^® group (P = 0.001). Furthermore, the effect of time on the fecal consistency score was significant (P = 0.047). The mean score of fecal consistency in both groups decreased over time. Conclusion: Goleghand^® was similar in efficacy to PEG for 8 weeks of pediatric functional constipation treatment in this randomized clinical trial. Goleghand^® can be considered as a new herbal laxative drug for pediatric functional constipation.