Both monopolar and bipolar recordings of human colonic myoelectrical activity have been made on 29 occasions from implanted serosal electrodes attached to either the ascending colon or transverse colon. Visual and computer analysis of the signals were made and the incidences of the two electrical rhythms present in the colon were compared for the two recording techniques, recording sites, and methods of analysis. The percentage incidence of both rhythms was similar for the mono and bipolar recording techniques in both parts of the colon. The incidence of the two rhythms in the transverse colon was approximately twice that recorded in the ascending colon, this being true for both recording techniques and methods of analysis, but neither was detected for more than 50% of the time. It is concluded that the methods of data analysis probably account for the differing incidences of electrical activity in the human colon that have been reported previously.