Effect of magnetic stimulation on the contractile activity of the rectum in the dog.
OBJECTIVE
Magnetic stimulation (MS) produces its effect, according to Faraday's law, by creating an electric field which can stimulate the neuromuscular tissues. The current study investigates, to our knowledge for the first time, the effect of MS on rectal pressure and evacuation with a view on its possible application in emptying the inertic or neuropathic rectum.


METHODS
The rectal, rectal neck and vesical pressures as well as the EMG activity of the two rectus abdominis muscles were recorded during sacral MS with a magnetic coil while the rectum was empty and while filled. Stimulation parameters were set at 70% intensity, 20 Hz frequency and 1- to 5-second burst length.


RESULTS
Sacral MS of both the filled and empty rectum effected a significant increase in rectal (p<0.01) and vesical (p<0.01) pressures and a decrease in rectal neck pressure (p<0.01). Rectal evacuation of the filled rectum using intermittent stimulation was achieved in all animals.


CONCLUSIONS
Sacral MS resulted in a rectal evacuation. It is a simple, easy and noninvasive method that might prove applicable in the treatment of inertic constipation and neuropathic rectum.
Department of Surgery and Experimental Research, Faculty of Medicine, Cairo University, Egypt.
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Shafik
D000818:Animals; D003248:Constipation / Q000628:therapy*; D004285:Dogs; D005260:Female; D008280:Magnetics / Q000627:therapeutic use*; D008297:Male; D009119:Muscle Contraction; D012007:Rectum / Q000502:physiology*