Introduction: Functional constipation is a common and often enduring problem in childhood. Although functional constipation is well defined by the Rome III criteria, these criteria have not always been integrated in general practice. Early diagnosis and treatment are key factors with respect to successful long-term outcome, as chronic constipation has a negative effect on the quality of life and is a burden for the public healthcare system. The safety of laxatives used for paediatric-functional constipation is based on well-designed trials carried out mostly in adults. Therefore, we conducted a review of the literature outlining the evidence for the efficacy and safety of laxatives used in chronic paediatric-functional constipation. Areas covered: This review clearly shows a lack of large well-designed placebo-controlled trials in children with constipation. Therefore, any interpretation with regards to the evidence for the effectiveness or safety of laxatives used in children is difficult and we extended the search for side effects to the adult literature. Expert opinion: In adults, new promising drugs are on the virtue of breaking through in the treatment of chronic constipation. Carrying out well-defined placebo-controlled trials in children should be the next step before using these drugs. © 2011 Informa UK, Ltd.