INTRODUCTION: Chronic constipation is a common childhood disorder that affects 5 to 10% of pediatric patients, being the second most common cause for seeking medical help, with the encopresis arising out of severe constipation being associated with fecal impaction in the rectum. Among diagnostic exams, anal manometry is used to evaluate patients with functional disorders such as constipation and fecal incontinence, and in some procedures for the evaluation of patients suffering from encopresis, as it provides information on the defecation mechanism and any potential anal sphincter injuries. OBJECTIVE: To verify manometric alterations in patients with encopresis. METHODS: A study was conducted based on 40 anal manometries of constipated children with encopresis (G1) and 12 constipated children without encopresis (G2). The following data were obtained: pressure at rest, contraction and evacuation of the anal canal and the rectal ampulla, point of highest pressure, anal inhibitory reflex and rectal sensitivity. The manometries were performed with an 8-channel perfusion device manufactured by Alacer. DISCUSSION: No differences were found with respect for pressures at rest, contraction and evacuation of the anal canal between groups. Our attention was drawn to the lack of need for an increased rectal volume to trigger the anal inhibitory reflex. There was no difference in the incidence of anismus between groups, which shows that it is not a relevant factor in the maintenance of the encopresis, but of constipation. CONCLUSION: An increase in rectal volume was not required to trigger the anal inhibitory reflex. Anismus was not different in the two groups, being unimportant in the maintenance of encopresis.
encopresis; fecal incontinence; manometry; constipation
