• colon;
  • humans;
  • manometry;
  • mass movements

Abstract Colonic contractile activity in man is still poorly understood and reported to be highly variable. In particular, little is known about colonic mass movements. We sought to gain greater information on mass movements by manometrically recording high-amplitude propagated contractions over three periods of 24 h in three healthy volunteers. Analysis of tracings showed that these events (a) are a relatively constant feature of the healthy colon (average [±SEM] number of mass movements for each subject was respectively 7 ± 1.7, 4 ± 1.5 and 6.3 ± 1.7); (b) display a diurnal variability, with a maximum of occurrence during the day and the waking state and a minimum during the night and the sleep; (c) are frequently related to specific physiological events