Although long-term esophageal manometry is increasingly used in clinical practice, the normal values of contraction parameters are poorly defined. In addition, limited data are available on the effect of age on esophageal motility. Therefore, 44 healthy subjects (age range: 22-85 years) were investigated with a probe combining two pressure transducers 10 cm apart. All subjects were asked to follow their normal daily routine. The characteristics of contraction events (amplitude, duration) and type of propagation (propulsive, simultaneous) were analyzed for the total time and predefined periods: meal, daytime (interprandial), and supine. Equally high distal and proximal median pressure amplitudes (39.5 and 37 hPa) and durations (3.4 and 3.2 sec) were observed. The median percentages of propulsive and simultaneous waves were 56% and 10%. The individual contraction characteristics differed significantly in these three selected periods for most motility parameters: distal and proximal pressure amplitudes, distal duration, and propulsive contractions. To evaluate the influence of age on normal values, the subjects were divided into two age groups (median age: 28.5 and 62.4 years). In the elderly group the distal pressure amplitude, the distal duration, and the percentage of simultaneous waves increased, whereas the percentage of propulsive waves, the proximal pressure amplitude, and the proximal duration decreased. However, the differences observed were only minor and rarely reached the level of statistical significance (distal pressure amplitude and duration in the supine period). In conclusion, the physiological motor activity of the esophagus is characterized by significant diurnal variation. Furthermore the motility data are little influenced by age.(ABSTRACT TRUNCATED AT 250 WORDS)