ELECTROMYOGRAPHIC ACTIVITY OF THE EXTERNA L ANAL-SPHINCTER MUSCLE ANDTHE PUBORECTAL MUSCLE DURING THE DEFECATION TEST IN PATIENTS WITH OBSTRUCTIVE DEFECATION DISORDER

In a prospective electromyographic and manometric study on 23 women (a verage age 52 years) with obstructive defecation disorder the activity of the external anal sphincter muscle and the puborectal muscle was i nvestigated at rest and during contraction and straining. The control group consisted of 22 healthy women with an average age of 53 years. T he main aim of the study was to investigate the functioning of the two muscles during simulated defecation (maximum strain) and to examine a ny changes in the pressure ratio in the rectum and the anal canal duri ng this stimulation. There were no significant differences in the rest ing pressure, the contraction pressure and the straining pressure (in the rectum and the anal canal) between the two groups. The functioning of the puborectal muscle and the external anal sphincter muscle was l argely the same in both the study group and the control group. No stat istically significant differences were found between the two groups ex cept in the amplitude of contraction. When we tried to list the change in the activity of the muscle as an index of anism, we were not able to objectify such a change for either the external anal sphincter musc le or the puborectal muscle. We therefore conclude that the increase i n the activity of the voluntary muscle of the pelvic floor observed on electromyography during defecation does not indicate a pathologic con dition but is a functional state.