Effect of bile acid perfusion on colonic motor function in patients with the irritable colon syndrome.

A study was performed to determine the effect of bile acid perfusion on motility in the sigmoid colon of patients with the irritable colon syndrome compared with normal subjects. Deoxycholic acid (15 mM) statistically significantly increased motility in normal subjects (control 25.0 +/- 6.4%, perfusion 71.4 +/- 7.2%, P < 0.05) but neither chenodeoxycholic acid nor cholic acid had any apparent effect. In patients with the irritable colon syndrome, however, deoxycholic acid at 5 mM concentration (control 29.8 +/- 4.2%, during perfusion 57.4 +/- 6.5%, P < 0.05) as well as at 15 mM concentration (control 19.4 +/- 5.7+, perfusion 57.8 +/- 9.6%, P < 0.05) statistically significantly increased rectosigmoid motility. Patients with the irritable colon syndrome had a high resting 0.033-0.066 Hz (2-4 c/m) electrical activity, whereas in normal subjects 0.1-0.15 Hz (6-9 c/m) activity was greater. However, there was no statistically significant alteration in either electrical rhythm during the period of bile acid perfusion. In conclusion, additional evidence is presented to suggest that deoxycholic acid is the only bile acid likely to be implicated in the motor disorder of the irritable colon syndrome.