EFFECTS OF PSYLLIUM THERAPY ON STOOL CHARACTERISTICS, COLON TRANSIT AND ANORECTAL FUNCTION IN CHRONIC IDIOPATHIC CONSTIPATION

Background: Psyllium is widely used in the symptomatic therapy of cons tipation, Its effects on colonic function and their correlation with s ymptomatic response have not been defined. Methods: After a 4-week bas eline, placebo, run-in phase, 22 subjects with idiopathic constipation confirmed by prospectively administered stool diaries were randomly a ssigned to receive either psyllium (5 g b.d., 11 patients) or placebo (11 patients) for 8 weeks, followed by another 4-week wash-out, placeb o phase, A colon transit study and anorectal manometry were performed at the beginning and at the end of each study phase, Subjects recorded , in diaries, their daily stool frequency, difficulty with defecation and weekly stool weight. Results: Stool frequency increased significan tly after 8 weeks of psyllium treatment (3.8 +/- 0.4 vs. 2.9 +/- 0.1 s tools/week, P < 0.05) as did stool weight (665.3 +/- 95.8 g vs. 405.2 +/- 75.9 g, P < 0.05). Subjects also reported an improvement in stool consistency (stool consistency score: 3.2 +/- 0.2 vs. 3.8 +/- 0.2, P < 0.05) and pain on defecation (pain score: 2.0 +/- 0.4 vs. 2.6. +/- 0. 5, P < 0.05) on psyllium. Colon transit and anorectal manometry parame ters were unchanged on psyllium. Subjects treated with placebo did not show any change in either subjective or objective measures of constip ation. Conclusions: Psyllium increases stool frequency and weight and improves stool consistency in idiopathic constipation. These effects a re not associated with significant changes in either colonic or rectal motor function. We suggest that the beneficial effects of psyllium in constipation are primarily related to a facilitation of the defecator y process.