What is the desirable stimulus to induce the rectoanal inhibitory reflex?
PURPOSE: This study was designed to find other methods to induce rectoanal inhibitory reflex. METHODS: Twenty healthy children were studied manometrically using three different types of stimuli, air, balloon, and water. RESULTS: Reflex occurred with all three kinds of stimuli; however, the free-air method was more sensitive and convenient than the common inflating balloon method. The lowest feeling amount and lowest amount in the free-air method are significantly lower than those in the balloon method (P < 0.05). The highest amount in the free-air method is significantly lower than those in the balloon method (P < 0.02). The highest drop and sustain time in both the free-air and balloon methods are not significant. CONCLUSIONS: The internal and sphincter has the function to respond to air (flatus). The semiconductor strain gauge catheter is better than the air-filled or water-filled balloon and water-infused catheter for the study of rectal physiology.
