Lack of utility of abdominal x-rays in the evaluation of children with constipation: comparison of different scoring methods.

Background and Aim: Abdominal x-rays are used diagnostically in the evaluation of children with constipation. However, their clinical utility has not been established. The aim of the study was to assess the accuracy of different methods in identifying children with functional constipation (FC) or nonretentive fecal incontinence (NRFI).
Patients and Methods: Retrospective review of abdominal x-rays in which colonic transit (CT), Barr, Leech, and fecal loading (FL) scores were blindly measured by blinded pediatric gastroenterologists and a radiologist. Children were classified a priori as FC or NRFI.
Results: One hundred sixty patients (125 FC, 35 NRFI) were studied. There were significant differences (P < 0.05) when comparing those with FC and those with NRFI: CT: 51 +/- 18 vs 40 +/- 21 hours; Barr: 14 +/- 5 vs 11 +/- 4; Leech: 10 +/- 2 vs 8 +/- 2; FL: 2 +/- 0.5 vs 1.7 +/- 0.4. More than 20% of FC had normal Barr and Leech scores, whereas >50% of NRFI had abnormal scores. CT discriminated better between FC and NRFI. There was a significant correlation (P < 0.05) between CT and Barr (0.45), Leech (0.41) and FL scores (0.36), and between Barr and Leech scores (r = 0.94). There was good intraobserver correlation between Barr, Leech, and FL scores but poor interobserver reproducibility.
Conclusions: Although significant differences in overall FC and NRFI scores exist, the discriminative value is low for all scores. There is poor interobserver reproducibility of the Barr, Leech, and FL scores. These findings confirm the limited value of the plain abdominal x-ray in the evaluation of children with constipation.