The role of interdigestive gallbladder emptying in gallstone formation is u
nknown. In fasting healthy subjects, gallbladder emptying is associated wit
h antral phase III of the migrating motor complex (MMC) and high plasma mot
ilin. Therefore, gallbladder volumes and motilin levels were measured durin
g 13 MMC cycles in 10 cholesterol gallstone patients and compared with 20 M
MC cycles in 10 healthy subjects. MMC cycle length was longer in gallstone
patients than in healthy subjects (158.2 +/- 17.0 vs 105.5 +/- 10.4 min, re
spectively; P < 0.05), due to longer phase I (39.8 +/- 5.7 vs 17.2 +/- 3.7
min, respectively; P < 0.05). In contrast to healthy subjects, gallstone pa
tients had no significant fluctuations of gallbladder volume during the MMC
cycle, and motilin concentrations were not different in MMC cycles with ph
ase III originating in antrum or duodenum. During MMC cycles with phase III
originating in the duodenum, motilin levels were twice as high in gallston
e patients as in healthy subjects (P < 0.002). In conclusion, cholesterol g
allstone patients have an abnormal MMC and motilin release pattern. Their i
nterdigestive gallbladder emptying is reduced and dissociated from the MMC.
These disturbances may contribute to gallstone formation.