Abstract:Objective To investigate the effects and the neurogenic mechanism of bisacodyl on colonic motor patterns in 3-taeniated rabbit colon in vitro. Methods The colonic motility of the 3-taeniated proximal colon of 34 male New Zealand rabbits were studied in the organ bath by spatio-temporal maps created from video recordings. Bisacodyl infusion and tetrodotoxin (TTX) in the bath were used to investigate the characteristics of the colonic motor patterns. Results ① Bisacodyl infusion induced rhythmic long distance contractions (LDCs); ② The prominent haustral boundary activity and fast propagating contraction were inhibited when rhythmic LDCs occurred; ③ The frequency of LDCs induced by bisacodyl in high concentration groups (0.15 mg/ml, 0.25 mg/ml) was higher than that in low concentration group (0.05 mg/ml, P < 0.05), but there was no significant difference in the duration, velocity and amplitude index of LDCs (P > 0.05); ④ These effects were blocked in the presence of TTX; LDCs was not induced by bisacodyl in the preconditioning of TTX. Conclusions Bisacodyl infusion induces LDCs through neurogenic pathway.