Constipation in school-aged children at public schools in Rio de Janeiro, Brazil

Constipation in childhood is a significant problem worldwide; however, understanding of its epidemiology is limited. Some investigators in the United States have estimated the prevalence of constipation to be 1.2% to 8.0% in the general population. In Brazil, some have found a prevalence of up to 36%.

This cross-sectional, descriptive, observational prevalence study included 391 pupils (age range, 8-10 years) who were attending three public education centers in Rio de Janeiro. The prevalence of constipation, associated symptoms, and dietary fiber intake were evaluated by questionnaire. A child was considered to be constipated when he or she reported difficulty in defecating two or more times per week. The children were divided into constipated and nonconstipated groups, and the presence of fecal soiling, blood in the feces, and shape of the feces were assessed.

Twenty-eight percent of the children were constipated. There was no significant difference between the sexes. Blood in the stools was significantly more frequently reported by the constipated children (p < 0.01). There was no significant difference in the prevalence and frequency of fecal soiling or in the stool shape between the constipated and nonconstipated children (p > 0.1). Fiber content in the diet ranged from 3.4 to 4.8 g per day, which is below the range recommended.

The prevalence of constipation in Rio de Janeiro is similar to the rates reported in all of Brazil and in a recent study from the United Kingdom but is much higher than that in the United States. In addition, the school menu was found to contain inadequate dietary fiber content.