Functional constipation is regarded as a long-standing symptomatic manifestation of abnormal defecation expressed either by a reduced frequency of bowel movements and/or by an altered act of evacuation. Patients with constipation can be treated with laxatives, diets, and regular habits. A thorough evaluation of functional constipation is considered when conservative treatment with dietary advice and use of laxatives fail. Patients with a normal colonic transit and normal anorectal function may only need reassurance, education and dietary advice with fiber supplementation. When such treatment modalities fail to relieve constipation, laxatives including bulkforming and osmotic agents may be used. Although most laxatives, if used intermittently, are relatively safe, possible side effects, patient compliance and their action mechanisms should be considered when choosing a laxative. A subgroup of patients with a slow colonic transit may not be managed by conventional laxatives, and may need enteroprokinetics or stimulant laxatives. This article reviews the assessment and pharmacological treatment of functional constipation.