Number of retained radiopaque markers on a colonic transit study does not correlate with symptom severity or quality of life in chronic constipation.

Background: Ingestion of radiopaque markers (ROM) is frequently used to determine colonic transit in chronic constipation. Although >= 20% of retained markers at 5 days defines slow-transit constipation, some clinicians use the number of retained markers to determine disease severity. Methods: We assembled a cross-sectional cohort of patients presenting for evaluation of chronic constipation who underwent transit testing by ROM and completed validated symptom severity and quality-of-life (QOL) measures. We performed a correlation analysis to determine whether there was an association between number of retained markers and symptom severity and QOL. Key Results: Among 159 patients undergoing evaluation for chronic constipation, there was poor correlation between the number of retained markers and symptom severity (R = .09, P = .25) and QOL. Among the 55 patients with slow-transit constipation defined by = 5 retained markers retained on day 5, there were similarly poor correlations between symptom severity (R = .17, P = .21) and QOL (R = .07, P = .60). Excluding patients with irritable bowel syndrome and outlet obstruction by balloon expulsion testing did not materially alter our results, nor did a multivariable analysis controlling for demographic and psychiatric confounders. Conclusions and Inferences: Among patients with chronic constipation, number of retained markers on a ROM colonic transit study does not correlate with measures of symptom severity or QOL. Clinicians should be cautious about overinterpreting ROM transit testing.