Colonic compliance, fasting tone, pressure thresholds for first perception, gas, and pain, and VAS scores of gas and pain during the phasic distentions were measured before administering the study medication and 1 hour after drug administration. After the postdrug assessment of sensation with phasic distentions, a 30-min assessment of fasting colonic tone was measured in each participant; this provided a baseline to compare the effect of a standard 750-ml chocolate milkshake meal across treatment groups. Postprandial tone was measured over 60 minutes, with the main focus on the first 30 minutes. When the recording was completed, the balloon was deflated and the tube removed by gentle traction.