The plain abdominal roentgenogram in the management of encopresis
R. M. Rockney, W. H. McQuade and A. L. Days
Department of Pediatrics, Brown University, Memorial Hospital, Pawtucket, RI 02860, USA.
OBJECTIVE: To determine whether fecal retention in encopretic children can
be assessed objectively using the plain abdominal roentgenogram and whether
roentgenographic evidence of fecal retention is associated with clinical
findings on presentation in encopretic children. DESIGN: Retrospective case
studies. SETTING: Two pediatric incontinence clinics. PARTICIPANTS: Sixty
children (72% male), aged 4 to 18 years (mean, 8 years), who met Diagnostic
and Statistical Manual of Mental Disorders, Revised Third Edition criteria
for the diagnosis of encopresis. All had a plain abdominal roentgenogram
obtained on presentation. INTERVENTIONS: None. RESULTS: Using a systematic
assessment tool with good interrater reliability (kappa = 0.65), 78% (47)
of the children had fecal retention by roentgenographic criteria on
presentation, while 22% (13) did not. Retentive encopretic children were
less likely to have a history of difficult toilet training (P = .018) than
nonretentive encopretic children. There was no association between fecal
retention and several clinical factors, including historical features
commonly attributed to fecal retention. Retentive encopretic children were
no more likely to have a palpable abdominal mass than nonretentive
encopretic children, but they were more likely to have excessive stool on
rectal examination (P = .015). Using the plain abdominal roentgenogram as
the gold standard, the rectal examination showed a positive predictive
value of 84.8% and a negative predictive value of 50% in assessing fecal
retention. CONCLUSIONS: Fecal retention in encopretic children can be
assessed objectively from a plain abdominal roentgenogram. Most, but not
all, encopretic children present with fecal retention. A positive rectal
examination is strongly predictive of fecal retention, in which case a
roentgenogram is not necessary to make that diagnosis. A negative rectal
examination may not rule out fecal retention, in which case an abdominal
roentgenogram may be useful to make that diagnosis.
