Intestinal disorders suggesting impaired gastrointestinal motility due to aging have been reported, but the influence of advanced age on the patterns of motility in the human small intestine is unknown. The present prospective study describes these patterns of motility in 15 healthy old subjects with a median of 84 years (range, 81-91 years). Nineteen healthy young adults served as controls. Ambulatory manometry was performed at home, with two sensors located in the proximal small intestine. Postprandial motility was induced by a standardized meal at 1800 h, and fasting motility was recorded during the subsequent night. Migrating motor complex (MMC) data were analysed by means of an expanded variance component model. Recurrent MMCs were identified during fasting in all individuals, with similar periodicity in old and young adults (p = 0.4). The propagation velocity of phase III of MMC was slower in the old subjects (6.5 +/- 0.8 cm/min versus 10.8 +/- 1.2 cm/min; p less than 0.01). Duration of postprandial motility was preserved, as were the amplitude and frequency of contractions during phase III and the postprandial state. Propagated clustered contractions were more frequently present in old subjects both after a meal (67% versus 11%; p less than 0.01) and during fasting (p less than 0.01); otherwise the patterns of motility are maintained in the human small intestine throughout the process of aging.