Authors' conclusions: There is no evidence to support the effectiveness of increased fluid intake, use of prebiotics, probiotics or behavioral therapy for the treatment of functional constipation. Only some evidence that shows some efficacy of dietary fiber.
Reviewers' commentary: This review contains a very small number of studies with great heterogeneity among them. These studies also are of small sample size. Therefore it is not possible to conclude from the results of this review, which treatment is more effective. Given the current state of knowledge on the subject, it seems prudent to recommend that the patient and their parents take preventive measures such as diets rich in fruits and vegetables and the acquisition of an appropriate intestinal habit. Should the patient require drug treatment, polyethylene glycol 3350 seems to be the best option.