Total and Segmental Colon Transit Time Study in Functional Constipation: Comparison With Healthy Subjects

BACKGROUND Constipation is a common problem worldwide. Constipation can be primary or secondary. Primary constipation is subdivided in slow transit constipation, normal transit constipation, and dyssynergic defecation. Colon transit time (CTT) is the most basic and primary tool in evaluating disorders of colonic motility. CTT helps to differentiate between types of constipation and plan the treatment. METHODS Fifty functional constipation patients and 25 healthy controls were asked to ingest four gelatin capsules (each containing five radio-opaque markers) at 0, 12 and 24 hours. An abdominal X-ray was taken at 36 hours. Total or segmental CTT was measured after calculating the number of markers remaining in each segment at 36 hours on abdominal X-ray. RESULTS Mean CTT in healthy controls in our study was 15.4 hours which is shorter than western population. Total CTT is significantly higher in constipation group (23 hours) compared to healthy subjects (15.4 hours). Transit time in right segment was significantly high in constipation group than healthy population (14.2 vs. 8.3 hours). Total as well as segmental transit times are slightly higher in females as compared to males in both the groups, however not statistically significant. To the best of our knowledge, there are no studies from India that compared the CTTs in functional constipation and healthy controls. CONCLUSION Radio-opaque marker study for CTT is a simple and reliable technique for evaluation of constipation. Patients with functional constipation have significantly longer CTT than healthy population. Total CTT is much less in this study population compared to west. There is need to establish standards for slow colon transit.