Electrical stimulation for anal sphincter control in barium enema examinations: an extended trial

The routine use in 500 consecutive patients of a barium enema cannula incorporating stimulating electrodes is described. Barium retention was improved by the electrically maintained contraction of the anal sphincter. The cannula was connected to a battery-powered control unit which provided the stimulus; pulse width was 1 msec and frequency was 20 pulses/sec. The pulse amplitude, adjusted for each patient, was in the range of 5--17V. A standard procedure was adopted throughout the trial without the use of colonic relaxants (such as anticholinergic drugs). The barium suspension and water were in stilled at body temperature. A comparison with a control series of 200 patients showed a significant reduction in the failure rate from 20% to 4%. No unpleasant side effects were encountered apart from a tingling sensation in the anal region which was expected. The principal factors contributing to failure were fecal impaction and diverticular disease.