ALTERED RECTAL PERCEPTION IS A BIOLOGICAL MARKER OF PATIENTS WITH IRRITABLE-BOWEL-SYNDROME

Background and Aims: Lowered visceral perception thresholds have been suggested as a biological marker of irritable bowel syndrome (IBS). Th e current study sought to determine the prevalence of altered rectal v isceral perception in patients with IBS and the correlation of altered perception thresholds with subjective symptoms. Methods: Anorectal ma nometry and rectal perception thresholds to balloon distention were de termined in 100 patients with IBS and 15 control subjects. Gastrointes tinal and psychological symptoms were assessed by questionnaire. Perce ption thresholds and symptoms were reassessed after 3 months in 15 pat ients with IBS. Results: Ninety-four percent of patients showed altere d rectal perception in the form of lowered thresholds for aversive sen sations (discomfort), increased intensity of sensations, or altered vi scerosomatic referral. Hypersensitivity was found only for aversive se nsations in response to rapid phasic distention; stool thresholds and thresholds in response to slow ramp distention were normal. Cluster an alysis by physiological parameters identified three IBS subgroups with predominant patterns of symptoms. Longitudinal evaluation indicated a correlation between changes in perception thresholds and symptom seve rity. Conclusions: Because altered rectal perception is present in alm ost all patients with IBS and perception thresholds correlate with tem poral changes in retrospective symptom severity, altered rectal percep tion represents a reliable biological marker of IBS.