Anorectal manometric abnormalities and effect of cisapride in patients with chronic idiopathic constipation

OBJECTIVES: To investigate abnormalities in anorectal motility, changes in rectal visceral perception of balloon distention and the effect of cisapride on patients with chronic idiopathic constipation (CIC). METHODS: Anorectal manometry was carried out in 30 CIC patients using the Synectics Visceral Stimulator combined with PcPolygraf before and after treatment with cisapride (10 mg three times daily for 4 weeks). Twenty age-matched controls were also studied before cisapride therapy. RESULTS: Patients with CIC had lower anorectal sphincter squeeze pressures (P < 0.05), larger minimum relaxation volumes necessary to elicit the anorectal inhibitory reflux (P < 0.05), higher rectal defecation volume thresholds and higher rectal maximum tolerable volume thresholds (P < 0.01) compared with the controls. All of the abnormalities significantly improved and defecation frequency greatly increased after 4 weeks of cisapride therapy (P < 0.01). Cisapride was effective in 46.67% of patients with CIC. CONCLUSIONS: Patients with CIC have abnormalities of both anorectal motility and rectal visceral perception of balloon distention. Cisapride can improve these abnormalities and is effective in approximately one-half of CIC cases.