Colonic transit study in patients with chronic constipation using Japanese-made radiopaque markers

A Colonic transit study (CTS) is useful and necessary for understanding the pathophysiology of disease that present with colonic motility dysfunction such as chronic constipation (CC). CTSs using radiopaque markers are a simple, safe, inexpensive, and easy to perform. However, no radiopaque markers are available and CTSs are not able to perform in Japanese clinical practice. Currently, we are working on the development of a domestically produced radiopaque markesr for measuring colonic transit time. The aim of this study was to ensure the safety of radiopaque markers under development. Five patients with CC who were receiving drug treatment were eligible for this study. The study participants ingested one gelatin capsule containing 24 radiopaque markers in the morning on Day 1. A single abdominal radiograph (posteroanterior) was performed 5 days after ingestion (Day 5) to count the number of radiopaque markers in the abdomen. No marker-related adverse effects were observed, and the safety of the radiopaque markers, which was the primary outcome of this study, was acceptable. Of the five patients who ingested the markers, only one had a residual marker on their abdominal radiograph after 5 days, and the marker was easily visible in this patient. We found no particular safety issues with the domestically produced radiopaque markers. However, further studies are required to examine the efficacy of these markers.