DISCRIMINATION OF IRRITABLE-BOWEL-SYNDROME BY NONLINEAR-ANALYSIS OF 24-H JEJUNAL MOTILITY

Conventional analysis of ambulatory long-term manometry of the small i ntestine has revealed abnormalities in patients with the irritable bow el syndrome (IBS). The aim was to use methods from non-linear dynamics , in particular the concepts of symbolic dynamics and entropy, in orde r to discriminate motility in IBS from healthy subjects. 24-h jeju nal motility was recorded in 30 IBS patients and 30 healthy subjects. Com puterized analysis oi contraction amplitudes and intercontractile inte rvals was performed. Both time series were analysed by symbolic dynami cs and entropy to quantify the degree of randomness inherent in the si gnal. During phase II IBS the intercontractile intervals (IBS: 0.978 /- 0.016, C: 0.965 +/- 0.020, P = 0.004) and for the contraction ampli tudes (IBS: 0.978 +/- 0.008, C: 0.970 +/- 0.026, P = 0.05) compared wi th healthy subjects. In addition, a (mmHg) was found in patients (IBS: 25.2 +/- 4.8, C: 22.2 +/- 3.1, P = 0.003). Considering a combination of both parameters, a diagnostic accuracy of 82% was achieved. We conc lude that phase II motility of the small intestine is more random in I BS than in health. Symbolic dynamics seems to be a promising new conce pt for the analysis of long-term gastrointestinal recordings.