Summary: The paper presents current knowledge about functional constipation in children regarding epidemiology, pathophysiology, diagnosis and management. Functional constipation is a common problem in childhood affecting up to 10% of children, with peak incidence between 2 and 4 years of age. The most common mechanism of developing this problem is withholding behavior. Stools remain in the rectum, the rectal mucosa reabsorbs water from the retained stools, which become more difficult and painful to evacuate. Diagnosis of functional constipation is based on the Rome IV Foundation criteria. Treatment requires a comprehensive approach that includes education of the parent and child, pharmacotherapy and program of regular toilet-sitting.