Figure 1. Method of detection of visceromotor response to colorectal distension. A distension balloon (5 cm long, flexible latex) was connected to a pressure-controlled balloon inflator that could inflate the distension balloon with air and that could control pressure within the distension balloon. A detection balloon (1.5 cm long, flexible latex) was located ahead of the distension balloon. The detection balloon was completely isolated from the pressure-controlled balloon inflator and far enough away (1.5 cm) from the rostral end of the distension balloon to avoid mechanical interference with the distension balloon. Pressures within the two balloons were recorded simultaneously.