[Spectral analysis of the electrical activity of the left colon]

The present study was conducted with the objective of carrying out a spectral analysis of the electrical activity of the left colon.

Seventeen female patients indicated for complete abdominal hysterectomies were studied. Three pairs of electrodes were implanted in the left colon. After the recuperation of the postoperative ileus, data was collected from the myoelectric activity of the colon from patients who were on an unrestricted diet and were being released from hospital. The signals of the electric activity of the colon were captured and fed into a computer, by means of a data collection system, DATAQ, Akron, OH, Series 200, which identified and captured frequencies between 0,02 and 10 Hz. The data was registered, stored and analysed using the software programme WINDAQ 200, for Windows. The acquisition data produced a sample of 40 points per second. For the electrical analysis, the average voltage of the electrical wave in the three electrodes of all the patients, expressed in millivolts, was considered, together with the maximum and minimum values, the RMS (root-mean-square), the skewness and the results of the Fast Fourier Transforms.

1. The average root-mean-square (RMS) in the left colon was 220,828 millivolts; 2. During a long period of contraction, the RMS was elevated in a statistically significant manner from 94,590 millivolts during a rest period to 487,950 millivolts.

The knowledge of the electrical characteristics of the colon resulting from this study, is one more stage in this line of research, where electromyographic alterations of the colon are studied. The definition and search for an electrical pattern of the colon should be a fundamental step in the clinical handling of physiopathological alterations of the colon.