Human interdigestive motility: variations in patterns from esophagus to colon.

In most fasting mammals, motility of the foregut and small intestine undergoes regular cycles of activity. Much of the expanding knowledge of this phenomenon comes from species other than humans; however, disorders of these patterns are proposed as being clinically important. We report studies in 16 healthy humans in whom motility was recorded from intraluminal pressure sensors, both when fasting and after a meal, for prolonged periods. The recording system spanned the area from stomach to proximal colon in all subjects and included the lower esophagus in 11 of the 16 studied. Half the interdigestive cycles involved the esophagus, approximately one-third began in the gastroduodenal region, and the remainder commenced more distally. Fewer than half the migrating motor complexes were recognizable beyond the midpoint of the small bowel, and less than 10% reached the distal ileum. The migrating motor complex was more prominent at night; and its progression through the jejunum was then slower. Small meals (345-395 kcal) interrupted fasting patterns for 90-240 min, but the amount of fat did not influence the duration of these disruptions. Motility varied widely between and within individuals, and differences between normal patterns in the jejunum and ileum were particularly striking. Thus, levels of recordings must be defined accurately if putative abnormalities, of possible clinical significance, are to be interpreted correctly. Relating local motor patterns to the maximal rate of rhythmic contractions, which reflects the frequency of slow waves and is a guide to the level of the small bowel, may be helpful in this regard.