Professionally administered colonic irrigations can often help to rebuild the muscle tone of the large intestine and restore natural peristalsis. Once the colon is cleansed of impacted waste matter, the introduction of water acts as resistance that stimulates the walls of the colon, much as a barbell acts as resistance to the muscles in the arms of a weight lifter.
The alternating inflow and release cycles during the colonic are in a way analogous to the repititions of a weight lifter as he or she strengthens the muscles in the arms and the colonic strengthens the muscles of the colon.
This effect is enhanced by the therapist alternating the temperature a few degrees cooler causing the muscles of the colon to contract, and then a few degrees warmer which allows the muscles to relax during each cycle.