Evaluation of colonic myoelectrical activity in health and functional disorders

Abstract

Electrical activity of the colon was investigated in 6 healthy volunteers and 22 patients presenting functional colonic disorders associated with pain, constipation, or diarrhoea. Myoelectrical activity during 10 hours, including 2 daily meals, was recorded from 8 groups of nickel-chrome electrodes using a 1.5 m length probe introduced by the rectal route. Electromyograms of volunteers consisted of slow waves at 2 distinct rhythms, approximately 3 and 10 cycles per minute, during 16 to 28% of the recording time respectively for each site. Action potentials were also recorded as 11 to 80 short spike bursts (SSB) per hour lasting 1.5 to 3.5 s at any site and 20-26 long spike bursts (LSB) per hour, lasting 17 to 21 s, occurring in series of 4 to 8 propagated bursts. Additional high-velocity propagated bursts were recorded during the 3 hour postprandial period. Three typical changes in spike activity patterns were detected: an increase by 170-420% of the number of SSB associated to a high spiking activity was recorded in 13 patients (group I), the absence of SSB, a low spiking activity level and only 3 to 8 LSB per hour (group II), in 6 patients; and the postprandial response was absent (group III) in 3 other investigated patients. Evidence for 3 groups of motor disturbances and their possible relation to clinical manifestations of functional disorders is presented.