Effects of a meal on the motility of the sigmoid colon and rectum in healthy adults.

Motility in the sigmoid and rectal areas was studied before, during, and after a 900-cal meal in 11 healthy subjects. A Honeywell esophageal pressure transducer with three transducers was used for the recording. A 900-cal meal significantly stimulated colonic motility during eating. The frequency of contractions was responsible for this increase while the amplitude of the contractions remained the same. Colonic motility returned to fasting levels immediately after the meal. Recording periods of 30 min were not capable of distinguishing individual variations in colonic motility because of long periods of inactivity but were adequate when groups of subjects were compared. Body position did not affect colonic motility. These studies suggest that a meal stimulates sigmoid and rectal motility in healthy subjects, but only during the consumption of the meal.