Under normal conditions a "physiologic malabsorption" and thus nutrients in the lower small intestine in the late postprandial state can be observed in humans. To study the effects of "physiologic" quantities of nutrients in the distal small intestine on upper gastrointestinal motor functions, 9 healthy subjects were intubated with an oro-ileal multi-lumen tube. The continuous perfusion of the duodenum with essential amino acids induced a fed motility pattern. In 12 out of 14 cases additional ileal perfusion with carbohydrates (60 kcal), but not with saline, converted the fed motility pattern to a pattern characteristic of the interdigestive state. These findings suggest that the ileum takes part in the late postprandial regulation of proximal gastrointestinal motor functions in humans.