Study of Reproducibility of Colonic Transit Study in Patients with Chronic Constipation

ABSTRACT

BACKGROUND: There are few reports about the reproducibility of colonic transit studies. Major therapeutic decisions are rendered based upon a single colonic transit study. Therefore, the aim of this study was to access the reproducibility of colonic transit studies in patients with chronic constipation. METHODS: Fifty one (51) patients with chronic constipation underwent two separate colonic transit studies. All clinical conditions, methodologies, and patients' instructions were identical on both occasions. The gamma rate (linear correlation analysis) was taken between the first and the second colonic transit studies. The patients were subdivided into those tested within the same year and those whose tests occurred more than 12 months apart. These two groups were further divided according to the diagnosis of colonic inertia, paradoxical puborectalis contraction, and chronic idiopathic constipation. RESULTS: In 35 of the 51 patients (69%), the results were identical between the two studies; however, in 16 patients (31%), the results were disparate (gamma correlation coefficient=0.53; p<0.01). The correlation coefficient for tests repeated within one year was 0.38 (p<0.05) whereas for periods greater than one year it was 0.72 (p<0.01). The specific correlation coefficients for patients with colonic inertia, paradoxical puborectalis contraction, and chronic idiopathic constipation were 0.12, 0.21, and 0.60 (p<0.05), respectively. CONCLUSIONS: Colonic transit studies are reproducible in patients with chronic constipation, regardless of the duration between tests. The correlation coefficient is best for patients with idiopathic constipation and worst for patients with colonic inertia.