Relevance of Colonic Gas Analysis and Transit Study in Patients With Chronic Constipation

BACKGROUND/AIMS: Colon transit time (CTT) is a useful diagnostic tool in chronic constipation, but requires good patient compliance. We analyzed the correlation between the gas volume score (GVS) and CTT in patients with chronic constipation. METHODS: The study included 145 consecutive patients (65 men) with chronic constipation. The primary outcome was the correlation be-tween the colon GVS and CTT. Secondary outcomes were the differences in colon GVS according to CTT and subtypes of chronic constipation. RESULTS: There were 81 patients with "CTT < 45 hours" and 64 patients with "CTT ≥ 45 hours." In addition, 88 patients were classi-fied as having functional constipation and 57 were classified as having constipation predominant irritable bowel syndrome (IBS-C). There was no significant correlation between CTT and colon GVS. However, the right colon GVS showed a positive cor-relation with right CTT (r = 0.255, P = 0.007). The median total colon GVS was significantly higher in patients with "CTT ≥ 45 hours" than in those with "CTT < 45 hours" (5.65% vs 4.15%, P = 0.010). There were no significant differences in colon GVS between the functional constipation and IBS-C. CONCLUSIONS: We were unable to detect a correlation between GVS and CTT in patients with chronic constipation. However, total colon GVS may be a method of predicting slow transit in patients with chronic constipation.