Anorectal manometry in children with chronic functional constipation.

Background: The anorectal manometry is a very utilized and well recognized examination in children with chronic functional constipation. The major manometric findings in these children are: anal hypotonia, anal hypertonia, paradoxal contraction of the external anal sphincter, decreased ability of internal anal sphincter to relax during rectal distension and alterations in rectal contractility, sensibility and compliance.

Aims: To evaluate the anal basal pressure and the relaxation reflex before and after standard treatment for a better understanding of the physiopathologic mechanisms involved in pediatric chronic functional constipation.

Methods: Anorectal manometry was performed before treatment on 20 children with chronic functional constipation aged 4 to 12 years and the results were compared to those obtained after standard treatment, with a good outcome.

Results: There was a reduction in anal basal pressure after treatment, but no differences were detected between the anorectal manometries performed before and after treatment in terms of amplitude and duration of relaxation, residual pressure, latency time, or descent and ascent angle.

Conclusions: We conclude that the anal basal pressure decreased in children recovering from chronic functional constipation, but the standard treatment did not provide all the conditions necessary for the relaxation reflex of constipated children to return to the values described in normal children.