Summary: Functional constipation is one of the most common gastrointestinal disorders in children and represents a significant challenge in everyday pediatric practice. Despite its high prevalence, this condition is still frequently underdiagnosed and inadequately treated, which may lead to chronic symptoms and the development of somatic and psychosocial complications. The vast majority of constipation cases in the pediatric population are functional in nature and are not associated with organic gastrointestinal disease. The diagnosis of functional constipation is based primarily on a thorough medical history and clinical assessment according to the Rome IV criteria, with particular attention to excluding alarm symptoms suggestive of organic pathology. The clinical presentation is heterogeneous and includes not only infrequent bowel movements and hard stools, but also painful defecation, retentive behaviors, abdominal pain, bloating, and fecal soiling. A key element in the pathophysiology of functional constipation is the vicious cycle of pain-related stool withholding. Management of functional constipation requires a comprehensive and long-term approach, combining patient and caregiver education, lifestyle and dietary modifications, and stepwise pharmacological therapy. Current ESPGHAN and NASPGHAN guidelines recommend polyethylene glycol (PEG) as the first-line treatment for both disimpaction and maintenance therapy. Due to their proven efficacy, favorable safety profile, and good tolerability, macrogols, including PEG 3350 and PEG 4000 formulations, constitute the cornerstone of contemporary treatment of functional constipation in children.