[Guidelines for the treatment of functional constipation]

Constipation is common in childhood. It can affect around 5-30% of the child population, depending on the criteria used for diagnosis. The currently recommended treatment is based on three main points: a) explanation, b) disimpaction and c) maintenance therapy consisting of diet changes, behavioural modification, and the use of laxatives. In the last decades treatment on disimpaction have changed radically from the rectal route to the oral route with polyethylene glycol 3350 (PEG), the most used and accepted regimen nowadays. Treatment and care should take into account the individual needs and preferences of the patient. Good communication is essential, to allow patients to reach informed decisions about their care. Maintenance therapy consists of dietary interventions, toilet training, and laxatives to obtain daily painless defaecation in order to prevent re-accumulation of stools. Maintenance therapy should be start as soon as the child's bowel is disimpacted. Early intervention with oral laxatives may improve complete resolution of functional constipation. Enemas using phosphate, mineral oil, or normal saline are effective in relieving rectal impaction, but carry the risk of mechanical trauma and are not recommended for maintenance therapy in the paediatric population. Among osmotic agents, polyethylene glycol 3350 plus electrolyte solutions appear to be the first-line drug treatment to use in children of any age, as it is safe, effective, and well-tolerated. Recommended doses ranges from 0.25 to 1.5g/kg. Advances in the understanding of the gastrointestinal enteric nervous system and epithelial function have led to the development of new substances that bind to serotonin receptors or are chloride channel activators.