Figure 4

Correlation between autonomic nervous system parameters and the presence of colonic reflexes in patients with chronic constipation using a Pearson correlation matrix. We assessed (A) high sympathetic (SI) tone (supine and baseline) and sympathetic (SI) reactivity to stimuli, (B) and (C) low parasympathetic (RSA, RMSSD) tone (supine and baseline) and parasympathetic reactivity to stimuli, and (D) overall sympathetic dominance as reflected in a high ratio of SI/RSA. Low parasympathetic tone during supine did not occur in any patient, thus was excluded. Correlations that are not theoretically associated (e.g. PBD does not stimulate the gastrocolic reflex) were excluded. Presence of low RSA and low RMSSD reactivity to meal and rectal bisacodyl showed a significant negative correlation with the presence of the coloanal reflex (CAR): all patients without the coloanal reflex had low RSA reactivity. * P < 0.05, **P < 0.01.