Comparison of Anorectal Function Tests according to the Types of Colon Transit Time in Patients with Chronic Idiopathic Constipation

Abstract

Background/Aims: The pathophysiology of chronic idiopathic constipation is complex. This study was designed to assess the usefulness of colon transit time as screening test in chronic idiopathic constipation. Methods: Colon transit time was evaluated in patients with chronic idiopathic constipation (n=38) in order to determine the type of colon transit time. The change of anorectal angle, perineal descent, rectocele, rectal intussusception, resting and squeezing anal sphincter pressure, and rectoanal inhibitory reflex were evaluated. Results: The abnormal change of anorectal angle at defecation was noted in 10.5% of patients with normal transit and 28.6% of patients with pelvic outlet obstruction. The descending perineum syndrome was observed in 10.5% of patients with normal transit, 25.0% of patients with colonic inertia, 25.0% of patients with hindgut dysfunction and 14.3% of patients with pelvic outlet obstruction. Rectocele greater than 2 cm was observed in 42.1% of patients with normal transit, 37.5% of patients with colonic inertia, 50.0% of patients with hindgut dysfunction and 57.1% of patients with pelvic outlet obstruction. Rectal intussusception severer than grade 3 was observed in 26.3% of patients with normal transit, 25.0% of patients with colonic inertia and 42.9% of patients with pelvic outlet obstruction. The high resting and squeezing anal sphincter pressure were observed in some with normal transit. Conclusions: These results suggest that defecography and anorectal manometry in addition to colon transit time are also recommended as screening test for chronic idiopathic constipation. (Kor J Gastroenterol 1999;33:348 - 357)