Background/Aims: The precise relationships among colonic motor pattern
s, depth of sleep, and awakening are incompletely understood. The aim
of this study was to correlate human colonic motor patterns with sleep
stage, nocturnal arousals, and waking. Methods: We monitored sleep an
d correlated sleep stage, arousals, and waking with pressures (area un
der curve and propagating contractions) recorded from the entire colon
in 11 healthy volunteers. Results: Propagating contraction frequency
(P = 0.01) and area under the curve (P = 0.001) were significantly red
uced at night. There was a highly significant correlation between dept
h of sleep and suppression of area under curve (P = 0.001) and propaga
ting contraction frequency (P = 0.0001). Propagating contractions were
eliminated during slow-wave sleep. During rapid eye movement sleep, c
olonic pressure and propagating contraction frequency increased sharpl
y to levels comparable with those found in stage 2 sleep. Transient ar
ousal from stable sleep, with or without waking, was a potent and imme
diate stimulus for colonic propagating contractions. Conclusions: Slee
p per se has a profound inhibitory effect on propagating and nonpropag
ating activity and is the major determinant of diurnal variation of co
lonic motility. Propagating contractions are eliminated in slow-wave s
leep. Rapid eye movement sleep, arousals, and waking have immediate st
imulatory effects on colonic motility.