Comorbidities Associated with Constipation in Children Referred for Colon Manometry May Mask Functional Diagnoses

BACKGROUND: In children with prolonged constipation of unclear pathogenesis or unresponsive to treatment, colon manometry can discriminate between functional fecal retention (FFR) and colon neuromuscular diseases. AIM: To identify the clinical features precipitating referral for colon manometry in children with functional constipation. METHOD: Retrospective medical record review of 173 constipated children (116 male, mean age 6.9 years, range 1-17 years) referred for colon manometry. RESULTS: Manometry was normal in 121 (70%). In those with normal manometry, FFR was identified in 96, irritable bowel syndrome (IBS) in 10, and functional constipation in 15. Of the 96 children FFR, 72 (76%) had comorbid conditions that might have interfered with the clinician's ability to diagnose FFR. Of 52 children with colon neuromuscular disease, only 12 (23%) had comorbid conditions (P < 0.001 compared with FFR). Of children more than 4 years, those with FFR were more likely to have fecal incontinence (44 of 62; 71%) than those with other functional disorders (2 of 19; 10%; P < 0.001) or neuromuscular disease (6 of 23; 26%; P < 0.001). CONCLUSIONS: Two thirds of children referred for colon manometry had normal studies and met criteria for a functional diagnosis. Three quarters of those with functional constipation had a comorbid condition that might alter the history sufficiently to obscure the diagnosis.